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114-461: The EMD F40PH is a four-axle 3,000–3,200 hp (2.2–2.4 MW) B-B diesel-electric locomotive built by General Motors Electro-Motive Division in several variants from 1975 to 1992. Intended for use on Amtrak 's short-haul passenger routes, it became the backbone of Amtrak's diesel fleet after the failure of the EMD SDP40F . The F40PH also found widespread use on commuter railroads in

228-496: A triple valve , also known as a control valve . Unlike the straight air system, the Westinghouse system uses a reduction in air pressure in the train line to indirectly apply the brakes. The triple valve is so named because it performs three functions: It allows air into an air tank ready to be used, it applies the brakes, and it releases them. In so doing, it supports certain other actions (i.e. it 'holds' or maintains

342-447: A "service rate reduction”, which means that the brake pipe pressure reduces at a controlled rate. It takes several seconds for the brake pipe pressure to reduce and consequently takes several seconds for the brakes to apply throughout the train. The speed of pressure changes during a service reduction is limited by the compressed air's ability to overcome the flow resistance of the relatively-small-diameter pipe and numerous elbows throughout

456-551: A 1,500-US-gallon (5,700 L; 1,200 imp gal) fuel tank. Subsequent units were built with a 1,800-US-gallon (6,800 L; 1,500 imp gal) tank. Beginning with the EMD F40PH-2 , introduced in 1985, the prime mover developed 3,200 horsepower (2.4 MW). Many of the original F40PHs were updated to match that output. The locomotives were 56 feet 2 inches (17.12 m) long. A standard F40PH weighs 260,000 lb (120,000 kg). For passenger service

570-476: A blown hose), the train breaking in two and uncoupling air hoses, or the engineer moving the automatic brake valve to the emergency position, will cause an emergency brake application . On the other hand, a slow leak that gradually reduces brake pipe pressure to zero, something that might happen if the air compressor is inoperative and therefore not maintaining main reservoir pressure, will not cause an emergency brake application. Electro-pneumatic or EP brakes are

684-596: A broken air brake hose) causes the air brakes to engage unexpectedly. An example of this problem can be seen in the accident that caused the death of John Luther "Casey" Jones on 30 April 1900 on the Illinois Central Railroad main line at Vaughan, Mississippi . The modern air brake is not identical with the original airbrake as there have been slight changes in the design of the triple valve, which are not completely compatible between versions, and which must therefore be introduced in phases. However,

798-520: A constant 893 RPM while supplying head end power (even standing still, with the throttle in idle). Power to the traction motors was controlled by varying the field excitation of the main (traction) generator. On some later versions of the F40PH (and on many rebuilt F40s), a second small auxiliary diesel engine at the rear of the locomotive powers the HEP alternator. In these engines, the prime-mover speed varies in

912-602: A forerunner to Metra , who ordered 74 between 1977 and 1983. Metra ordered 41 more between 1988 and 1992. Other agencies who bought the F40PH included the Massachusetts Bay Transit Authority (MBTA) (18), Caltrain (20), GO Transit (6), New Jersey Transit (17), and VIA Rail (59). Finally, the rail construction firm Speno ordered four. In total EMD built 449 locomotives, including the F40PHR trade-ins. The F40PH performed well for Amtrak: at

1026-718: A hinge. Examples include the Milwaukee Road EF-1 "Boxcab" electrics. "B+B-B+B" means there are four trucks under the unit. Within each truck, there are two powered axles, and pairs of them are connected by span bolsters . One example would be the General Electric U50 , built from 1963 to 1965. The 4500 horsepower (3.4 MW) turbine locomotives built by GE for Union Pacific also used this arrangement. The EFVM railway of Brazil uses narrow gauge GE "BB" locomotives with this arrangement, both with "standard" and wide cabs. A GE Dash 9-40BBW , for instance,

1140-554: A leading idler axle in front of two powered axles. This arrangement was used to upgrade the B-B arrangement of two EMC 1800 hp B-B locomotives owned by the Santa Fe Railroad in 1938, for greater stability at speed. "1-D" means there are two trucks or groups of axles; the "1" truck is under the front of the unit, and has one idler axle. The remaining 4 axles are rigidly mounted to the frame behind this lead truck (or grouped in

1254-502: A long time a three-wire version of the electro-pneumatic brake, which gives up to seven levels of braking force. In North America , the Westinghouse Air Brake Company supplied high-speed control brake equipment for several post- World War II streamlined passenger trains. This was an electrically controlled overlay on conventional D-22 passenger and 24-RL locomotive brake equipment. On the conventional side,

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1368-403: A matter of preference by the locomotive builder or the railroad. In some systems, the automatic and independent applications will be additive; in some systems the greater of the two will apply to the locomotive consist. The independent system also provides a bail off mechanism, which releases the brakes on the lead locomotives without affecting the brake application on the rest of the train. In

1482-489: A non-rebuilt Caltrain F40PH-2 locomotive. AAR wheel arrangement#B-B The AAR system (like UIC) counts axles, unlike Whyte, which counts wheels. Letters refer to powered axles, and numbers to unpowered (or idler) axles. "A" refers to one powered axle, "B" to two powered axles in a row, "C" to three powered axles in a row, and "D" to four powered axles in a row. "1" refers to one idler axle, and "2" to two idler axles in

1596-433: A number of safeguards that are usually taken to prevent this sort of accident from happening. Railroads have strict government-approved procedures for testing the air brake systems when making up trains in a yard or picking up cars en route. These generally involve connecting the air brake hoses, charging up the brake system, setting the brakes and manually inspecting the cars to ensure the brakes are applied, and then releasing

1710-491: A number of the retired units into baggage / cab cars . Colloquially known as "cabbages" (a portmanteau of "cab" and "baggage"), and officially known as Non-Powered Control Units (NPCUs), these units had their diesel engines, traction motors, and main alternators removed, as well as a large roll-up door installed in the side (allowing the former engine compartment to be used for baggage). Amtrak converted 22 locomotives into cabbage cars between 1996 and 2007. Each converted unit

1824-410: A pair of high-powered B-B locomotives on a common frame as far as traction and power was concerned). In fact, a usual consist of a D-D unit included a leading C-C unit and a trailing C-C unit, for a total of about 12,600 hp (9.4 MW) (with four total prime-movers). With today's higher horsepower C-C units (about 4,300 hp (3.2 MW) apiece), three such C-C units exceeds the total power of

1938-587: A row. The "A1A" truck is under the rear of the unit, and has one powered axle, one idler axle, and one more powered axle. An example is the FM OP800 800 hp (600 kW) railcar, six of which were built by the St. Louis Car Company exclusively for the Southern Railway in 1939. "2-B" means there are two trucks or wheel assemblies. The "2" truck is under the front of the unit, and has two idler axles in

2052-502: A row. A dash ("–") separates trucks or wheel assemblies. A plus sign ("+") refers to articulation, either by connecting bogies with span bolsters or by connecting individual locomotives via solid drawbars instead of couplers . "1A-A1" means there are two trucks (or wheel assemblies) under the unit. Each truck has one powered axle and one idler axle, with the idler axles to the outside. Examples include Budd RDC diesel multiple unit ( DMU ) cars. "1B-1B" means there are two trucks with

2166-527: A row. The "B" truck is under the rear of the unit, and has two powered axles. Examples include the three lightweight power cars built by ALCO / ACF in 1935 and 1937 for use with the Rebel streamliners. "3-A1A" means there are two trucks or wheel assemblies. The "3" truck is under the front of the unit, and has three idler axles in a row. The "A1A" truck is under the rear of the unit, and has one powered axle, one idler axle, and one more powered axle. An example

2280-529: A second truck). This is roughly the equivalent of a 2-8-0 Consolidation in the Whyte notation, particularly when built as a 1-truck/4 rigid axle locomotive. The only known examples are a series of diesel boxcab locomotives built and owned by the Texas Mexican Railway . "2-A1A" means there are two trucks or wheel assemblies. The "2" truck is under the front of the unit, and has two idler axles in

2394-517: A separate HEP generator. These were designated F40PH-2C and F40PH-CAT where Cummins and Caterpillar generators were used, respectively. The F40PH-2C was considerably heavier than the standard design, weighing 282,000 lb (128,000 kg). The F40PH-2D , employed by Via Rail, had special customizations for operating in Canada, including ditch lights . Metra's last 30 locomotives, designated F40PHM-2 (now rebuilt as F40PHM-3 ), were built with

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2508-529: A sloped cab similar to the experimental EMD F69PHAC . The streamlined appearance acquired the nickname " Winnebago ." Speno's four locomotives, designated F40PH-2M , were delivered without turbochargers , limiting power output to 2,000 horsepower (1,500 kW). The five EMD GP40 locomotives Morrison-Knudsen rebuilt for Tri-Rail in 1988 were designated F40PHL-2 . Progress Rail rebuilt 41 Metra units with remanufactured engines, rebuilt traction motors and microprocessor traction control. These have been designated

2622-605: A third headlight addition, cab reconditioning, additional safety horns at the front, and repainting into the newer VIA scheme. Rebuilt locomotive No. 6403, pulling the Canadian through the Rocky Mountains , was included on the back of the redesigned Canadian ten-dollar note in 2013 (The actual 6403 was later renumbered to 6459.) As of 2018, VIA has 53 such EMD F40PH locomotives in service. VIA started another round of rebuilding for 39 F40PH-2D locomotives in 2024, with

2736-805: A type of air brake that allows for immediate application of brakes throughout the train instead of the sequential application. EP brakes have been in British practice since 1949 and also used in German high-speed trains (most notably the ICE ) since the late 1980s; they are fully described in Electro-pneumatic brake system on British railway trains . As of 2005 , electro-pneumatic brakes were in testing in North America and South Africa on captive service ore and coal trains. Passenger trains have had for

2850-490: Is "Four axle". "B-2-B" means there are three trucks. The center truck has two unpowered axles and the truck at each end has two powered axles. The locomotive frame must either articulate or allow for significant side play to be provided to the center truck. Examples of this type were built as light rail vehicles. "B-B-B" means there are three trucks. Each truck has two powered axles. The locomotive frame must either articulate or allow for significant side play to be provided to

2964-408: Is "Six axle". "1-C+C-1" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with one idler axle, and inboard of it are three powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The PRR FF1 and FF2 electric locomotives used this arrangement. "2-C+C-2" means there are two sets of articulated axles under

3078-523: Is a guiding truck with two idler axles, and inboard of this, and hinged to it, is a truck with three powered axles. The GE steam turbine-electric locomotives of 1939 were notable examples of this arrangement. "2-C1+2-C1-B" means there are five trucks. Only the first three axles on the four-axle trucks were powered, as were both axles in the last truck; the first and middle trucks had two unpowered axles each. The only examples of this arrangement were three unique coal -fired steam-turbine locomotives built by

3192-410: Is a little simpler than the air brake. Instead of an air compressor, steam engines have an ejector with no moving parts, and diesel or electric locomotives have a mechanical or electrical "exhauster". Disconnection taps at the ends of cars are not required because the loose hoses are sucked onto a mounting block. However, the maximum pressure in a vacuum system is limited to atmospheric pressure, so all

3306-584: Is a narrow-gauge adaptation of the SD45 , which required additional axles due to using smaller traction motors. "2-D+D-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. Examples include the Baldwin DR-12-8-1500/2 "Centipede" diesel locomotives and

3420-751: Is a truck with two idler axles, and inboard of it are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The Little Joes , Baldwin DR-12-8-1500/2 , and Baldwin 4-8+8-4-750/8-DE locomotives used this arrangement. "D-D" means there are two trucks each with four powered axles. Examples include the EMD DD units. D-D locomotives have fallen out of favor as nearly all of these were twin-engined locomotives, which placed too much horsepower in too few axles which made these consists rather inflexible (each locomotive featured two prime movers , making each unit essentially

3534-399: Is a wide cab GE Dash 9-40CW series 4,000 hp (3,000 kW) locomotive with a B+B-B+B wheel arrangement. The EMD SD70ACe-BB produced from 2015 onward also has a B+B-B+B arrangement. "B-B+B-B" means that the locomotive has four trucks. Each truck contains two powered axles. The middle pair of trucks are connected by a span bolster . In most cases, the locomotive is articulated over

EMD F40PH - Misplaced Pages Continue

3648-403: Is an indication that the cars' triple valves are malfunctioning. Depending on the location of the air test, the repair facilities available, and regulations governing the number of inoperative brakes permitted in a train, the car may be set out for repair or taken to the next terminal where it can be repaired. A different kind of accident can occur if a malfunction in the air brake system (such as

3762-472: Is based on and aligned with UIC Leaflet 540, a document ratified by many train-operating companies. UIC Leaflet 540 explicitly approves the following brake systems: Historically, and according to UIC 540, we distinguish systems technically approved since 1927-1932 such as: Westinghouse W , Knorr K , Kunze-Knorr , Drolshammer, Bozic, Hildebrand-Knorr. In the steam era, Britain's railways were divided–some using vacuum brakes and some using air brakes–but there

3876-477: Is called the automatic brake and provides service and emergency braking control for the entire train. The locomotive(s) at the head of the train (the "lead consist") have a secondary system called the independent brake. The independent brake is a "straight air" system that makes brake applications on the head-of-train locomotive consist independently of the automatic brake, providing for more nuanced train control. The two braking systems may interact differently as

3990-461: Is divided into two portions: the service section, which contains the mechanism used during brake applications made during service reductions, and the emergency section, which senses the faster emergency reduction of train line pressure. In addition, each car's air brake reservoir is divided into two sections—the service portion and the emergency portion—and is known as the "dual-compartment reservoir”. Normal service applications transfer air pressure from

4104-606: Is featured on the reverse of the Frontier series Canadian $ 10 bill . The F40PHs are still a common sight on many other commuter railroads throughout the United States. In addition, Amtrak has kept 22 of its F40PHs in use as non-powered control units . Amtrak inherited an aging and mechanically incompatible fleet of diesel locomotives from various private railroads on its startup in 1971. The most modern locomotives remained in private hands for freight service, or to operate

4218-407: Is the later built FM OP800 800 hp (600 kW) railcar, six of which were built by the St. Louis Car Company exclusively for the Southern Railway in 1939. "A1-1A" means there are two trucks or wheel assemblies under the unit. Each truck has one powered axle and one idler axle, with the powered axles to the outside. "A1A-2" means there are two trucks. The "A1A" truck is under the front of

4332-414: Is thus fail-safe —any failure in the train line, including a separation ("break-in-two") of the train, will cause a loss of train line pressure, causing the brakes to be applied and bringing the train to a stop, thus preventing a runaway train. Modern air brake systems serve two functions: When the train brakes are applied during normal operation, the engine operator makes a "service application" or

4446-551: Is under the back of the unit, and has one idler axle. Examples include the three EMD LWT12 locomotives built by EMD in 1956. Twenty SD70ACe-P4 locomotives were built by EMD with a B1-1B arrangement that has two three axle trucks with each truck having two AC traction motors and one idler axle nearest the fuel tank. The locomotive was designed as an AC traction alternative to the SD70M-2 that uses three DC traction motors on each of two three axle trucks. Only BNSF ordered

4560-531: Is under the back of the unit, and has three idler axles in a row. An example is the Baldwin DR-6-2-10 1,000 hp (750 kW) cab unit, only one of which was built for the Chicago and North Western Railway in 1948. "A1A-A1A" means there are two trucks under the locomotive. Each truck has two powered axles, with an idler axle between them. This spreads the weight of the locomotive more evenly over

4674-465: Is under the back of the unit, and has two idler axles in a row. Examples include the three lightweight RP-210 locomotives built by Baldwin in 1956 and 1957 for use with Pullman-Standard Train-X equipment. "B-A1A" means there are two trucks. The "B" truck is under the front of the unit, and has two powered axles. The "A1A" truck is under the back of the unit, and has one powered axle, one idler axle, and one more powered axle. Examples include some of

EMD F40PH - Misplaced Pages Continue

4788-458: Is where the locomotive's air compressor output is stored and is ultimately the source of compressed air for all connected systems. Since the main reservoir pipe is kept constantly pressurized by the locomotive, the car reservoirs can be charged independently of the brake pipe, this being accomplished via a check valve to prevent backfeeding into the pipe. This arrangement helps to reduce the above-described pressure loss problems, and also reduces

4902-598: The 1953 Pennsylvania Railroad train wreck involving the Federal Express , a Pennsylvania Railroad passenger train which became a runaway while heading into Washington Union Station in Washington, D.C. , causing the train to crash into the passenger concourse and fall through the floor. Similarly, in the Gare de Lyon rail accident , a valve was accidentally closed by the crew, reducing braking power. There are

5016-758: The Baldwin Locomotive Works for the Chesapeake and Ohio Railway between 1947 and 1948. This locomotive is sometimes called the M-1. "C-C+C-C" means there are four trucks under the unit. Each truck has three powered axles. The only examples of this type were the 8500 horsepower (6.3 MW) turbine locomotives built by General Electric for Union Pacific . These locomotives consisted of two permanently coupled C-C units. "C+C-C+C" means there are four trucks. Each truck has three powered axles and pairs of them are connected by span bolsters . This arrangement

5130-834: The British Rail Class 28 are the only locomotives to use this wheel arrangement. "C-C" means there are two identical trucks. Each truck has three powered axles. Examples include the EMD SD (Special Duty), GMD GF6C , EMD GM6C , PRR E44 , GE E60 , Virginian EL-C and GE Evolution Series units, except the ES44C4 and ET44C4 which use the A1A-A1A wheel arrangement. This is a currently popular configuration used in low-speed, high-weight applications, such as unit coal trains. General ("manifest") freight trains also use C-C locomotives. See also Co-Co . An American colloquialism of "C-C"

5244-543: The F40PH-3 . The MBTA's dozen F40PHM-2C locomotives were built new using EMD components, as were the six F40PH-3C locomotives of the Altamont Commuter Express built by MotivePower. The MBTA's F40PH-2C and F40PHM-2 locomotives were later rebuilt by MotivePower into F40PH-3C locomotives starting in 2019. As Amtrak's F40PH fleet was replaced by newer GE Genesis -series locomotives, Amtrak converted

5358-517: The F40PH-4C . These feature a remanufactured Tier 0+ prime mover and a separate Tier 4 HEP generator, as well as microprocessor controls. The first of these locomotives, numbered "1001", was unveiled in Boston in mid-October 2024. Electro-Motive Division manufactured 475 F40PHs of all types between 1975 and 1992. The orders for GO Transit and VIA Rail Canada were built by General Motors Diesel (GMD),

5472-931: The FM C-liners (most passenger units) built from 1950 to 1955, and the EMD FL9 . "B-B" means there are two identical trucks. Each truck has two powered axles, a currently popular configuration used in high-speed, low-weight applications such as intermodal trains and high-speed rail , as well as switcher locomotives . Examples include the EMD GP (General Purpose), EMD F-units , EMD SW1500 , Acela Express Power Cars , Siemens Charger , Siemens ACS-64 and GE Genesis units. High speed ("time") freight trains, with guaranteed schedules often use B-B locomotives of 3,800 HP (950 HP per axle), but this application, too, has largely been replaced by higher-powered, 4,500 HP C-C locomotives (750 HP per axle). An American colloquialism of "B-B"

5586-621: The GE " Little Joe " electric locomotives . "B-D+D-B" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two powered axles, and inboard of it are four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The W-1 class of electric locomotives built by General Electric for the Great Northern Railway used this arrangement. "1B+D+D+B1" means there are four sets of articulated axles under

5700-535: The Great Northern Z-1 electric locomotives (for the Cascade Tunnel electrification) used this arrangement. "2-D-2" means there are three trucks. At either end are trucks with two idler axles; the center truck has four powered axles. The PRR R1 electric locomotive used this arrangement. "2-D+D-2" means there are two sets of articulated axles under the unit. Within each of these sets, theare

5814-691: The San Luis and Rio Grande Railroad and formerly the Canadian American Railroad , was regeared for a maximum speed of 65 miles per hour (105 km/h) and given an enlarged 2,900 US gallons (11,000 L; 2,400 imp gal) fuel tank. It was also fitted with a door, platform, and steps at the front. One unit, 450, was acquired by Western Maryland Scenic Railroad in 2018. In 2023-2024, Rolling Stock Solutions, an American locomotive leasing company, rebuilt several F40PH locomotives for leasing to commuter rail operators and dubbed them

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5928-708: The Virginian Railway 's EL-2B electric locomotives. Railway air brake A railway air brake is a railway brake power braking system with compressed air as the operating medium. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on April 13, 1869. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell Westinghouse's invention. In various forms, it has been nearly universally adopted. The Westinghouse system uses air pressure to charge air reservoirs (tanks) on each car. Full air pressure causes each car to release

6042-411: The rate of brake pipe pressure reduction. Therefore, as long as a sufficient volume of air can be rapidly vented from the brake pipe, each car's triple valve will cause an emergency brake application. However, if the brake pipe pressure is too low due to an excessive number of brake applications, an emergency application will not produce a large enough volume of air flow to trip the triple valves, leaving

6156-539: The "stars of Amtrak's long-distance trains". However, two events led to a major change in thinking within Amtrak regarding the EMD SDP40F. The first event was a sharp decline in the mechanical reliability of the EMD SDP40F, including several derailments. The second event was the unusually harsh winter of 1976–1977 , which sidelined many of Amtrak's aging steam-heated coaches. Amtrak suspended numerous routes and pressed

6270-424: The F40PH has another electrical alternator, the head-end generator . The HEP unit generates three-phase AC power at 480 V (500 kW on the first order, 800 kW on later units) for lighting, heating and air-conditioning the train. Originally, F40PHs powered the HEP alternator from the prime mover. As a result of that, the train had to be at a constant 60 Hz frequency, and the prime mover had to turn at

6384-471: The F40PH-2. The F40PH-2s delivered to Caltrain incorporated Southern Pacific Railroad -style headlights. The designation "F40PH" stood for the following: "F" for the full-width cowl carbody, "40" as the locomotive is part of EMD's 40-series (based on the GP40-2 freight locomotive), "P" for passenger service, and "H" for head-end power. Amtrak ordered its first 30 EMD F40PHs on May 8, 1975. The first of

6498-505: The UK, the Class 31 uses this wheel arrangement. "A1A-B+B" means there are three trucks. The first truck has three axles, with the center one unpowered. A pair of two-axle trucks, each with both axles powered, are connected by a span bolster under the rear of the unit. The only example to date of this arrangement was a single experimental EMD SDP45 . "B" means there are two powered axles under

6612-467: The United States and with VIA Rail in Canada. Additional F40PH variants were manufactured by Morrison-Knudsen and MotivePower between 1988 and 1998, mostly rebuilt from older locomotives. Amtrak retired its fleet of F40PHs in the early-2000s in favor of the GE Genesis , but the locomotive remains the mainstay of VIA Rail's long-distance trains; a depiction of the locomotive hauling The Canadian

6726-410: The air from the train line and vent the coupling hoses for uncoupling cars. The air brake only operates if the angle cocks are open except the ones at the front of the locomotive and at the end of the train. The air brake can fail if one of the angle cocks is accidentally closed. In this case, the brakes on the wagons behind the closed cock will fail to respond to the driver's command. This happened in

6840-441: The application and it permits the exhaust of brake cylinder pressure and the recharging of the reservoir during the release). In his patent application, Westinghouse refers to his 'triple-valve device' because of the three component valvular parts comprising it: the diaphragm-operated poppet valve feeding reservoir air to the brake cylinder, the reservoir charging valve, and the brake cylinder release valve. Westinghouse soon improved

6954-466: The basic air brakes used on railways worldwide are remarkably compatible. European brake systems vary between countries, but the working principle is the same as for the Westinghouse air brake. European passenger cars used on national railway networks must comply with TSI LOC&PAS regulation, which specifies in section 4.2.4.3 that all brake systems must adhere to the EN 14198:2004 standard. This standard

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7068-401: The brake pipe's pressure directly to atmosphere. This serves to more rapidly vent the brake pipe and hasten the propagation of the emergency reduction rate along the entire length of the train. Use of distributed power (i.e., remotely controlled locomotive units mid-train and/or at the rear end) somewhat mitigates the time-lag problem with long trains, because a telemetered radio signal from

7182-573: The brake pipe, the rate of reduction is highest near the front of the train (in the case of an engine operator-initiated emergency application) or near the break in the brake pipe (in the case of loss of brake pipe integrity). Farther away from the source of the emergency application, the rate of reduction can be reduced to the point where triple valves will not detect the application as an emergency reduction. To prevent this, each triple valve's emergency portion contains an auxiliary vent port, which, when activated by an emergency application, also locally vents

7296-411: The brakes and manually inspecting the cars to ensure the brakes are released. Particular attention is usually paid to the rearmost car of the train, either by manual inspection or via an automated end-of-train device , to ensure that brake pipe continuity exists throughout the entire train. When brake pipe continuity exists throughout the train, failure of the brakes to apply or release on one or more cars

7410-508: The brakes must be applied before recharging has been completed, a larger brake pipe reduction will be required in order to achieve the desired amount of braking effort, as the system is starting out at a lower point of equilibrium (lower overall pressure). If many brake pipe reductions are made in short succession ("fanning the brake" in railroad slang), a point may be reached where car reservoir pressure will be severely depleted, resulting in substantially reduced brake cylinder piston force, causing

7524-425: The brakes to fail. On a descending grade , the result will be a runaway. In the event of a loss of braking due to reservoir depletion, the engine driver may be able to regain control with an emergency brake application, as the emergency portion of each car's dual-compartment reservoir should be fully charged—it is not affected by normal service reductions. The triple valves detect an emergency reduction based on

7638-408: The brakes. A subsequent reduction or loss of air pressure causes each car to apply its brakes, using the compressed air stored in its reservoirs. In the air brake's simplest form, called the straight air system , compressed air pushes on a piston in a cylinder. The piston is connected through mechanical linkage to brake shoes that can rub on the train wheels, using the resulting friction to slow

7752-505: The center truck. The Russian VL85 and US-American EMD GM10B was a notable example. See also Bo-Bo-Bo . "B+B+B" means there are three articulated sets of two powered axles each under the unit. The locomotive frame must allow for significant side play to be provided to the center axle set, as well as allowing for end play for the end sets. The ten Mexican Railway GE boxcab electrics of 1923 are examples of this wheel arrangement. "2-B+B-2" means there are two sets of articulated axles under

7866-438: The center trucks. "B-B+B-B+B-B" means that the locomotive has six trucks. Each truck contains two powered axles. The only known locomotives to have this configuration were the two EMD TR3 locomotives made of three permanently coupled B-B units, which had solid drawbars connecting the units instead of the typical couplers. "C" means there are three powered axles under the unit. They are not articulated relative to other parts of

7980-741: The company's Canadian subsidiary. Morrison-Knudsen (M-K) and its successor MotivePower (MPI) remanufactured another 31 locomotives between 1988 and 1998. Three ex-Amtrak F40PHs have been preserved: Two Coaster F40PHM-2C locomotives have been preserved: No. 2103 at the Pacific Southwest Railway Museum and No. 2105 at the Southern California Railway Museum . In October 2024, the Southern California Railway Museum began fundraising in hopes of preserving

8094-466: The control valve set a reference pressure in a volume, which set brake cylinder pressure via a relay valve. On the electric side, pressure from a second straight-air trainline controlled the relay valve via a two-way check valve. This "straight air" trainline was charged (from reservoirs on each car) and released by magnet valves on each car, controlled electrically by a three-wire trainline, in turn controlled by an electro-pneumatic master controller in

8208-423: The controlling locomotive. This controller compared the pressure in the straight air trainline with that supplied by a self-lapping portion of the engineers valve, signaling all of the "apply" or "release" magnets valves in the train to open simultaneously, changing the pressure in the straight-air trainline much more rapidly and evenly than possible by simply supplying air directly from the locomotive. The relay valve

8322-408: The device by removing the poppet valve action. These three components became the piston valve, the slide valve, and the graduating valve. When the engine operator applies the brake by operating the locomotive brake valve, the train line vents to atmosphere at a controlled rate, reducing the train line pressure and in turn triggering the triple valve on each car to feed air into its brake cylinder. When

8436-563: The electric GE E60 CP) curtailed further orders of that unit when Amtrak found itself needing more short- and medium-distance power in the spring of 1975. The design of the F40PH was based on the EMD GP40-2 freight road switcher locomotive and shared that locomotive's turbocharged EMD 645 E3 V16 cylinder, two-stroke, water-cooled diesel engine ( prime mover ). The prime mover developed 3,000 hp (2.2 MW) at 893 RPM. The main (traction) generator converts mechanical energy from

8550-419: The engine driver with no means to stop the train. To prevent a runaway due to loss of brake pressure, dynamic (rheostatic) braking can be utilized so the locomotive(s) will assist in retarding the train. Often, blended braking , the simultaneous application of dynamic and train brakes, will be used to maintain a safe speed and keep the slack bunched on descending grades. Care would then be given when releasing

8664-416: The engine operator in the front locomotive commands the distant units to initiate brake pressure reductions that propagate quickly through nearby cars. Many modern air brake systems use distributors instead of triple valves. These serve the same function as triple valves, but have additional functionality such as the ability to partially release the brakes. The locomotive's air compressor typically charges

8778-404: The engine operator releases the brake, the locomotive brake valve portal to atmosphere is closed, allowing the train line to be recharged by the compressor of the locomotive. The subsequent increase of train line pressure causes the triple valves on each car to discharge the contents of the brake cylinder to the atmosphere, releasing the brakes and recharging the reservoirs. The Westinghouse system

8892-416: The engineer moves the automatic brake handle to a "service" position, which causes a reduction in brake pipe pressure. During normal service, the pressure in the brake pipe is never reduced to zero and in fact, the smallest reduction that will cause a satisfactory brake response is used to conserve brake pipe pressure. A sudden and substantial pressure reduction caused by a loss of brake pipe integrity (e.g.,

9006-400: The equipment has to be much larger and heavier to compensate. That disadvantage is made worse at high altitude. The vacuum brake is also considerably slower to both apply and release the brake, which requires a greater level of skill and anticipation from the driver. Conversely, the vacuum brake originally had the advantage of allowing gradual release, whereas the Westinghouse automatic air brake

9120-494: The event the train needs to make an emergency stop, the engine operator can make an "emergency application," which will rapidly vent all of the brake pipe pressure to atmosphere, resulting in a faster application of the train's brakes. An emergency application also results when the integrity of the brake pipe is lost, as all air will also be immediately vented to atmosphere. An emergency brake application brings in an additional component of each car's air brake system. The triple valve

9234-422: The goal of extending their lifespan to 2035. These F40PH locomotives are now supplemented by GE P42DC locomotives delivered in 2001 and by Siemens SCV-42 locomotives delivered in 2023. The longevity of the F40PH has led to numerous conversions, rebuildings, and remanufacturings. In some instances new locomotives were assembled using EMD components. Several transit agencies lengthened their locomotives to include

9348-439: The larger fuel tank and more powerful HEP generator which had become standard. Amtrak ultimately acquired 132 F40PHRs in this manner — which combined with new orders between 1975 and 1988 and with the purchase of six GMD F40PHs from GO Transit in 1990 — led to a fleet of 216 locomotives, the country's largest fleet. The first commuter rail operator to order F40PHs was Chicago's Regional Transportation Authority (RTA) ,

9462-700: The last P42DC, and their last regular assignment was on the Maple Leaf in December 2001. The Panama Canal Railway acquired several ex-Amtrak F40PHs for both freight and passenger service; the 480V head-end power matched the voltage used by the refrigeration in Maersk Sealand containers. The EMD F40PH has continued to serve VIA Rail into the 21st century: between 2007 and 2012 VIA refurbished its entire fleet for CAD $ 100 million. The rebuild program included separate HEP generators, overhauled engines,

9576-403: The length of the train, and the relatively-small exhaust port on the head-end locomotive, which means the brakes of the rear-most cars will apply sometime after those of the forward-most cars apply, so some slack run-in can be expected. The gradual reduction in brake pipe pressure will mitigate this effect. Modern locomotives employ two air brake systems. The system which controls the brake pipe

9690-509: The locomotive. This arrangement is only used on very small locomotives (e.g. the PRR B1 ). This arrangement is sometimes referred to as 0-6-0 , the Whyte notation equivalent. "C-B" means there are two trucks. The "C" truck is under the front of the unit, and has three powered axles. The "B" truck is under the rear of the unit, and has two powered axles. The Japanese DE10 , DE11 , and DE15 and

9804-429: The loss of the force applying the brakes. This could easily cause a runaway train . Straight air brakes are still used on locomotives, although as a dual circuit system, usually with each bogie (truck) having its own circuit. In order to design a system without the shortcomings of the straight air system, Westinghouse invented a system wherein each piece of railroad rolling stock was equipped with an air reservoir and

9918-460: The main reservoir with air at 125–140 psi (8.6–9.7 bar; 860–970 kPa). The train brakes are released by admitting reduced and regulated main reservoir air pressure to the brake pipe through the engineer's automatic brake valve. In America, a fully charged brake pipe typically operates at 90 psi (6.2 bar; 620 kPa) for freight trains and 110 psi (7.6 bar; 760 kPa) for passenger trains. The brakes are applied when

10032-477: The model in 2014. The other locomotive with this wheel arrangement is the EMD SD70MACH , which is an SD70MAC rebuilt by Progress Rail for Metra and used for passenger service. In 2020, Metra approved of the purchase of 15 of these locomotives with options to purchase up to 27 more. "B-2" means there are two trucks. The "B" truck is under the front of the unit, and has two powered axles. The "2" truck

10146-549: The new HEP -equipped Amfleet I coaches, designed for short runs, into service. The F40PH, with its built-in HEP generator, was the natural choice to haul these coaches. As problems with the EMD SDP40F mounted, Amtrak adopted the F40PH as its long-term solution nationwide for diesel engine service. In the spring of 1977 Amtrak traded 40 EMD SDP40Fs back to EMD. Components including the prime mover were installed into an EMD F40PH frame. The 40 rebuilt locomotives, designated F40PHR , were identical to new-build EMD F40PHs, incorporating

10260-520: The new locomotives entered service on April 9, 1976. Amtrak intended the locomotives for short routes such as the San Diegan in California and Northeast Corridor services in the then non-electrified route portion between New Haven, Connecticut and Boston, Massachusetts . The long-distance routes were protected by the then-new EMD SDP40F , described by J. David Ingles in late 1975 as

10374-474: The prime mover into electricity distributed through a high voltage cabinet to the traction motors . Each of the four traction motors is geared to a pair of driving wheels ; the gear ratio determines the maximum speed of the locomotive. A standard F40PH has a gear ratio of 57:20, permitting a maximum speed of 103 mph (166 km/h). Some Amtrak F40PHs were delivered with a 56:21 gearing for 110 mph (177 km/h). The first 30 locomotives were built with

10488-435: The reporting back of performance of each wagon's brakes. The Westinghouse air brake system is very reliable but not infallible. The car reservoirs recharge only when the brake pipe pressure is higher than the reservoir pressure. Fully recharging the reservoirs on a long train can require considerable time (8 to 10 minutes in some cases ), during which the brake pipe pressure will be lower than locomotive reservoir pressure. If

10602-447: The service and dynamic brakes to prevent draw-gear damage caused by a sudden run out of the train's slack. Another solution to loss of brake pressure is the two-pipe system, fitted on most locomotive-hauled passenger stock and many freight wagons. In addition to the traditional brake pipe, this enhancement adds the main reservoir pipe, which is continuously charged with air directly from the locomotive's main reservoir. The main reservoir

10716-413: The service section to the brake cylinder, while emergency applications cause the triple valve to direct all air in both the sections of the dual-compartment reservoir to the brake cylinder, resulting in a 20 to 30 percent stronger application. The emergency portion of each triple valve is activated by the higher rate of reduction of brake pipe pressure. Due to the length of trains and the small diameter of

10830-509: The span bolster. The Union Pacific 's M-10002 diesel streamliner and New York Central 's T-Motor third-rail electric locomotives are examples of this type. This arrangement also includes locomotives made of two permanently coupled B-B units, such as some EMD FT units which had a solid drawbar connecting two units instead of the typical couplers. "B-B-B-B" means there are four trucks. Each truck has two powered axles. The locomotive frame must allow for significant side play to be provided to

10944-573: The start of the 1990s only four had been retired due to wrecks. The locomotive was at the center of Amtrak's advertising. Trains magazine estimated that on average, each F40PH traveled as many as 175,000 miles (282,000 km) a year. Amtrak began replacing the F40PH with the GE Dash 8-32BWH in 1991, the GE P40DC in 1993, and the GE P42DC in 1996. All were retired by 2001 with the arrival of

11058-496: The system were not dependent on each other in any way, and any or all of these options could be supplied separately. Later systems replace the automatic air brake with an electrical wire which runs in a circle round the whole train and has to be kept energized to keep the brakes off. In the UK it is known as a train wire . It is routed through various "governors" (switches operated by air pressure) which monitor critical components such as compressors, brake pipes and air reservoirs. If

11172-413: The time required for the brakes to release, since the brake pipe only has to recharge itself. Main reservoir pipe pressure can also be used to supply air for auxiliary systems such as pneumatic door operators or air suspension. Nearly all passenger trains (all in the UK and USA), and many freights, now have the two-pipe system. At both ends of each car, there are angle cocks fitted. These valves cut off

11286-494: The track and counteracts the tendency of trucks to oscillate at high speeds, which is a problem with two axle trucks. The idler wheels may be smaller than the powered wheels. Examples of locomotives with this wheel arrangement include the EMD E-units and ALCO PAs , which were high speed passenger locomotives, and the dual service FM Erie-built . BNSF took delivery of ES44C4 locomotives with this type of truck in 2009. In

11400-412: The train divides, the wire will be broken, ensuring that all motors are switched off and both portions of the train have an immediate emergency brake application . More recent innovations are electronically controlled pneumatic brakes where the brakes of all the wagons (cars) and locomotives are connected by a kind of local area network , which allows individual control of the brakes on each wagon, and

11514-463: The train. The mechanical linkage can become quite elaborate, as it evenly distributes force from one pressurized air cylinder to 8 or 12 wheels. The pressurized air comes from an air compressor in the locomotive and is sent from car to car by a train line made up of pipes beneath each car and hoses between cars. The principal problem with the straight air braking system is that any separation between hoses and pipes causes loss of air pressure and hence

11628-546: The unit, and has one powered axle, one idler axle, and one more powered axle. The "2" truck is under the back of the unit, and has two idler axles in a row. An example is the Silver Charger power car for the General Pershing Zephyr . "A1A-3" means there are two trucks. The "A1A" truck is under the front of the unit, and has one powered axle, one idler axle, and one more powered axle. The "3" truck

11742-462: The unit. At each end, there is one unpowered axle and two powered axles, hinged to a set of four powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The "Bi-Polar" electric locomotives used by the Milwaukee Road used this arrangement. "(B+B-B+B)+(B+B-B+B)" means there are 2 units, each with 4 trucks in a B+B-B+B wheel arrangement. An example was

11856-466: The unit. These axles are not articulated relative to other parts of the locomotive. This arrangement is only used on very small locomotives, such as the EMD Model 40 . It is also used on speeders . This arrangement is sometimes referred to as 0-4-0 , the Whyte notation equivalent. "B-1" means there are two trucks. The "B" truck is under the front of the unit, and has two powered axles. The "1" truck

11970-420: The unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are three powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The Pennsylvania Railroad 's GG1 and Companhia Paulista 's electric locomotives were notable examples of this arrangement. "2+C-C+2" means there are two sets of axles under the unit. Within each of these sets, there

12084-570: The unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are two powered axles. Two of these articulated sets are placed back to back and connected by a hinge. The PRR DD1 and DD2 electric locomotives used this arrangement. "2-B+B+B+B-2" means there are two sets of articulated axles under the unit. Within each of these sets, there is a truck with two idler axles, and inboard of it are two powered axles, hinged to yet another set of two powered axles. Two of these articulated sets are placed back to back and connected by

12198-499: The usual D-D consist by 300 hp (220 kW) (with one fewer prime-mover than a usual D-D consist, thereby significantly improving reliability and dramatically reducing maintenance). Although the D-D arrangement is associated with twin-prime-mover locomotives of high power, this does not mean a D-D with a single high-power prime mover may be built in the future, nor does it exclude two-truck, eight-axle electric locomotive. The EMD DDM45

12312-419: The usual way. They can be identified by the diesel exhaust at the rear of the locomotive and by their quiet idle. Remaining F40s, with the constant-RPM prime movers, are noticeably louder. In the initial design the battery box and air reservoirs were located forward of the fuel tank. In locomotives manufactured after 1977 these were relocated behind the tank. The battery box returned to its original location in

12426-465: The various commuter services which, by law, did not pass to Amtrak. To replace these Amtrak ordered 150 EMD SDP40F locomotives, which began entering service in 1973. These were supplemented by 25 GE P30CHs which entered service in 1975. The SDP40F was a troubled design; problems with weight distribution led to a series of derailments in the mid-1970s. Meanwhile, the poor truck design of the P30CH (and

12540-514: Was a gradual standardization on the vacuum brake. Some locomotives, e.g. on the London, Brighton and South Coast Railway , were dual-fitted so that they could work with either vacuum- or air-braked trains. In the diesel era, the process was reversed and British Railways switched from vacuum-braked to air-braked rolling stock in the 1960s. The main competitor to the air brake is the vacuum brake, which operates on negative pressure. The vacuum brake

12654-563: Was equipped with four diaphragms, magnet valves, electric control equipment, and an axle-mounted speed sensor, so that at speeds over 60 mph (97 km/h) full braking force was applied, and reduced in steps at 60, 40 and 20 mph (97, 64 and 32 km/h), bringing the train to a gentle stop. Each axle was also equipped with anti-lock brake equipment. The combination minimized braking distances, allowing more full-speed running between stops. The straight-air (electro-pneumatic trainline) , anti-lock, and speed graduating portions of

12768-437: Was originally available in only the direct-release form still common in freight service. A primary fault of vacuum brakes is the inability to find leaks easily. In a positive air system, a leak is quickly found due to the escaping pressurized air. Discovering a vacuum leak is more difficult, although it is easier to repair, because a piece of rubber (for example) can just be tied around the leak and will be firmly held in place by

12882-464: Was renumbered by prefixing "90" to its original number. In 2011, Amtrak converted F40PH No. 406 (later renumbered 90406) to an NPCU to enable push-pull operation of Amtrak's 40th-anniversary exhibit train; in addition, a HEP generator was installed to supply auxiliary power. However, unlike other NPCUs, it resembles an operational F40PH externally. Some F40PHs found their way into freight service, after suitable modifications. The F40M-2F , which runs on

12996-679: Was used on the Jawn Henry coal -fired steam-turbine locomotive built by the Baldwin Locomotive Works for the Norfolk & Western Railway in May, 1954. "1-D-1" means there are three trucks under the unit. At either end are trucks with one idler axle; the center truck has four powered axles. The original 1904–1909 New York Central S-Motor third-rail electric locomotives (for the Grand Central Terminal electrification) and

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