100-448: The East Broad Top Railroad (EBT) is a 3 ft ( 914 mm ) narrow gauge historic and heritage railroad headquartered in Rockhill Furnace, Pennsylvania . Operating from 1871 to 1956, it is one of the United States' oldest and best-preserved narrow-gauge railroads, and was designated a National Historic Landmark in 1964. The railroad is now preserved for use as a tourist attraction until operations ceased in 2011. After
200-411: A calcium aluminate cement or with Portland cement to form Portland cement concrete (named for its visual resemblance to Portland stone ). Many other non-cementitious types of concrete exist with other methods of binding aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces , and polymer concretes that use polymers as a binder. Concrete
300-659: A track gauge of 3 ft ( 914 mm ) or 1 yard . This gauge is a narrow gauge and is generally found throughout North , Central , and South America . In Ireland , many secondary and industrial lines were built to 3 ft gauge, and it is the dominant gauge on the Isle of Man , where it is known as the Manx Standard Gauge . Modern 3 ft gauge railways are most commonly found in isolated mountainous areas, on small islands, or in large-scale amusement parks and theme parks (see table below). This gauge
400-433: A French structural and civil engineer . Concrete components or structures are compressed by tendon cables during, or after, their fabrication in order to strengthen them against tensile forces developing when put in service. Freyssinet patented the technique on 2 October 1928. Concrete is an artificial composite material , comprising a matrix of cementitious binder (typically Portland cement paste or asphalt ) and
500-452: A cementitious material forms a cement paste by the process of hydration. The cement paste glues the aggregate together, fills voids within it, and makes it flow more freely. As stated by Abrams' law , a lower water-to-cement ratio yields a stronger, more durable concrete, whereas more water gives a freer-flowing concrete with a higher slump . The hydration of cement involves many concurrent reactions. The process involves polymerization ,
600-603: A complete structural repair on the Rockhill Shops. The FEBT Restoration crew will perform the balance of the needed work of this project. A contractor has been secured to install a fire suppression system throughout the Shops Complex and Roundhouse. Several large scale track rebuilding projects were executed around the Rockhill yard. Thousands of ties were delivered to Rockhill to rehabilitate the tourist portion of
700-400: A concrete component—and become a part of the binder for the aggregate. Fly ash and slag can enhance some properties of concrete such as fresh properties and durability. Alternatively, other materials can also be used as a concrete binder: the most prevalent substitute is asphalt , which is used as the binder in asphalt concrete . Admixtures are added to modify the cure rate or properties of
800-513: A cover story, "Is It a Sin to be Narrow Gauge?", in Trains . But coal demand was already plummeting as homes and industries switched to cheap oil and gas. The last nail in the coffin came when the silica brick plants in Mount Union converted to oil and gas and not enough coal could be sold to support the mines and the railroad. The railroad closed as a coal hauler April 14, 1956, and along with
900-434: A dispersed phase or "filler" of aggregate (typically a rocky material, loose stones, and sand). The binder "glues" the filler together to form a synthetic conglomerate . Many types of concrete are available, determined by the formulations of binders and the types of aggregate used to suit the application of the engineered material. These variables determine strength and density, as well as chemical and thermal resistance of
1000-452: A greater degree of fracture resistance even in seismically active environments. Roman concrete is significantly more resistant to erosion by seawater than modern concrete; it used pyroclastic materials which react with seawater to form Al- tobermorite crystals over time. The use of hot mixing and the presence of lime clasts are thought to give the concrete a self-healing ability, where cracks that form become filled with calcite that prevents
1100-415: A large aggregate that is too large for the size of the formwork, or which has too few smaller aggregate grades to serve to fill the gaps between the larger grades, or using too little or too much sand for the same reason, or using too little water, or too much cement, or even using jagged crushed stone instead of smoother round aggregate such as pebbles. Any combination of these factors and others may result in
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#17327906985631200-461: A large type of industrial facility called a concrete plant , or often a batch plant. The usual method of placement is casting in formwork , which holds the mix in shape until it has set enough to hold its shape unaided. Concrete plants come in two main types, ready-mix plants and central mix plants. A ready-mix plant blends all of the solid ingredients, while a central mix does the same but adds water. A central-mix plant offers more precise control of
1300-540: A lease to the East Broad Top Railroad Preservation Association , a non-profit founded with the intention of acquiring the railroad and reactivating all 33 miles (53 km) of the railroad's original main line (only 5 miles (8.0 km) operated for tourist operations). The EBTPA made a number of improvements on site as well as adding numerous special events like Day Out with Thomas and Polar Express. In 2011, EBTPA extended
1400-469: A mixture of calcium silicates ( alite , belite ), aluminates and ferrites —compounds, which will react with water. Portland cement and similar materials are made by heating limestone (a source of calcium) with clay or shale (a source of silicon, aluminium and iron) and grinding this product (called clinker ) with a source of sulfate (most commonly gypsum ). Cement kilns are extremely large, complex, and inherently dusty industrial installations. Of
1500-598: A new group of investors began to acquire right-of-way in 1867 and was able to construct the railroad as a 3 ft ( 914 mm ) narrow gauge line in 1872–1874. Service began from Mount Union, Pennsylvania to Orbisonia, Pennsylvania in August, 1873, and to Robertsdale in November, 1874. The line later was extended to Woodvale and Alvan, with several short branches. At its height, it had over 60 miles of track and approximately 33 miles of main line. The primary purpose of
1600-463: A nine-year closure, in February 2020 it was announced that the railroad had been purchased by a non-profit foundation and regular train service resumed in the summer of 2021. The EBT is unusual in that it is a complete, original railroad rather than a collection of pieces from various locations, as most tourist railroads are. All six of the 3 ft narrow-gauge steam locomotives that operated on
1700-405: A number of manufactured aggregates, including air-cooled blast furnace slag and bottom ash are also permitted. The size distribution of the aggregate determines how much binder is required. Aggregate with a very even size distribution has the biggest gaps whereas adding aggregate with smaller particles tends to fill these gaps. The binder must fill the gaps between the aggregate as well as paste
1800-621: A pair of Babcock & Wilcox boilers, a 19th-century stationary steam engine, and an overhead line shaft system (steel shafts, wood and iron pulleys and leather and canvas belts) that powers antique machine tools , sheet-forming machines, foundry equipment, blacksmithing tools and woodworking machines. Almost 33 miles (53 km) of the railroad's original line is still in place, though only 5 miles (8.0 km) are usable. In recent years, disused trackage from Rockhill Furnace southward and Robertsdale southward have been cleared and gauged for use with speeders and handcars (track-gang cars). The EBT
1900-424: A semi-liquid slurry (paste) that can be shaped, typically by pouring it into a form. The concrete solidifies and hardens through a chemical process called hydration . The water reacts with the cement, which bonds the other components together, creating a robust, stone-like material. Other cementitious materials, such as fly ash and slag cement , are sometimes added—either pre-blended with the cement or directly as
2000-493: A simple, fast way of getting a basic idea of the properties of the finished concrete without having to perform testing in advance. Various governing bodies (such as British Standards ) define nominal mix ratios into a number of grades, usually ranging from lower compressive strength to higher compressive strength. The grades usually indicate the 28-day cure strength. Thorough mixing is essential to produce uniform, high-quality concrete. Separate paste mixing has shown that
2100-406: A solid over time. Concrete is the second-most-used substance in the world after water , and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined. When aggregate is mixed with dry Portland cement and water , the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts with
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#17327906985632200-471: Is also popular in model railroading (particularly in G scale ), and model prototypes of these railways have been made by several model train brands around the world, such as Accucraft Trains (US), Aristo-Craft Trains (US), Bachmann Industries (Hong Kong) , Delton Locomotive Works (US), LGB (Germany) , and PIKO (Germany) . The Ferrocarril de Sóller and the Tranvía de Sóller are located on Majorca in
2300-511: Is distinct from mortar . Whereas concrete is itself a building material, mortar is a bonding agent that typically holds bricks , tiles and other masonry units together. Grout is another material associated with concrete and cement. It does not contain coarse aggregates and is usually either pourable or thixotropic , and is used to fill gaps between masonry components or coarse aggregate which has already been put in place. Some methods of concrete manufacture and repair involve pumping grout into
2400-742: Is located in the East Broad Top Robertsdale Station, about 40 minutes from the operating portion of the railroad, and contains historic artifacts and documents. Robertsdale was hub of the coal mining operations of the Rockhill Iron and Coal Company which hauled the coal on the EBT. The goal of the FEBT Museum is to present the history and culture of the East Broad Top Railroad and Coal Company and
2500-489: Is no timetable for its return to service. No. 14 would follow after that. In July 2022, the railroad took delivery of the first of four newly constructed passenger cars. Constructed by a Bellingham, Washington -based company. They resemble 1890s era passenger cars but with amenities such as electric lighting, baseboard heating, and modern lavatories. One car is a baggage/combine with wheelchair lifts. The EBT once kept two-standard gauge Baldwin 0-6-0 switching locomotives at
2600-502: Is providing funding and contractors for major work, and the FEBT continues to cover moderate and smaller portions of projects, as well as larger, non-pending projects. As of October 2020 yard trackage at Robertsdale, which is approximately 19 miles from the heritage Rockhill Furnace station, was cleared of brush, and the scale track in front of the depot was restored. Three coal hopper cars were transported by flatbed truck for display and marked
2700-559: Is then blended with aggregates and any remaining batch water and final mixing is completed in conventional concrete mixing equipment. Workability is the ability of a fresh (plastic) concrete mix to fill the form/mold properly with the desired work (pouring, pumping, spreading, tamping, vibration) and without reducing the concrete's quality. Workability depends on water content, aggregate (shape and size distribution), cementitious content and age (level of hydration ) and can be modified by adding chemical admixtures, like superplasticizer. Raising
2800-399: Is usually reinforced with materials that are strong in tension, typically steel rebar . The mix design depends on the type of structure being built, how the concrete is mixed and delivered, and how it is placed to form the structure. Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, mortar , and many plasters . It consists of
2900-548: The Balearic Islands . The other railways of the Majorca rail network were also 3 ft ( 914 mm ) gauge, but with expansion and reconstruction of the network in the early 2000s, they were converted to 1,000 mm ( 3 ft 3 + 3 ⁄ 8 in ) metre gauge . Concrete Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to
3000-480: The construction industry , whose demand is ever growing with greater impacts on raw material extraction, waste generation and landfill practices. Concrete production is the process of mixing together the various ingredients—water, aggregate, cement, and any additives—to produce concrete. Concrete production is time-sensitive. Once the ingredients are mixed, workers must put the concrete in place before it hardens. In modern usage, most concrete production takes place in
3100-497: The 1995 Gettysburg Railroad boiler explosion led to the eventual retirement of many of the Mikados. #12 last operated in 2000, #17 in 2001, and #14 in 2005. Engine #15 was overhauled in the early 2000s and returned to service in 2005, allowing it to remain in service until the railroad ceased operations at the end of 2011. During the closure, the railroad facilities were maintained by a skeleton staff of paid employees and Friends of
East Broad Top Railroad and Coal Company - Misplaced Pages Continue
3200-597: The EBT (now re-laid with 4 ft 8 + 1 ⁄ 2 in or 1,435 mm standard gauge ), which follows Blacklog Creek. While the trolley museum is an entirely separate entity, it coordinates its schedules with the EBT. FEBT operates a museum complex in the community of Robertsdale in Wood Township, Pennsylvania known as the Friends of the East Broad Top Museum . The museum
3300-686: The EBT Foundation, had purchased the railroad, and planned to restart excursions in 2021. The sale included approximately 27 miles of line, the yard complex in Rockhill Furnace, and all associated rolling stock and equipment. Financial details of the sale have not been disclosed. The EBTF board includes notable rail preservationists Bennett Levin and Henry Posner III , former CEO of both Norfolk Southern Railway and Amtrak , Charles "Wick" Moorman and longtime EBT activists Lawrence Biemiller, Brad Esposito and David Brightbill. The sale of
3400-642: The EBT considered this switch unnecessary. Steam locomotives had proven longevity and, as EBT was a coal carrier, fuel was abundant and cheap. In 1929 the EBT formed the East Broad Top Transit Company and operated regional bus service. It acquired the Mount Union Bus Line in 1931. In 1941 this operation was sold to the Huntingdon Bus Company . In November 1953 the railroad's innovation earned them
3500-603: The EBT. The Friends of the East Broad Top continued many ongoing and new restoration projects in Rockhill Furnace throughout the closure of the railroad, with the active encouragement of owner Joe Kovalchick. FEBT also assisted with routine site maintenance and repair of the EBT Facilities. Tours of the Historic Shops complex were initially offered only for groups of 20 or more by prior arrangement with
3600-402: The East Broad Top (FEBT) volunteers. FRA inspections and paperwork were kept up on locomotive #15 in preparation for a possible reopening. Although no public excursions were held from 2012 to 2019, diesel-powered trains were operated for members of the FEBT on October 6, 2012 and October 12, 2013, as well as an M-1 excursion to McMullens Summit. Motorcar excursions were also operated for members of
3700-571: The FEBT attending its annual Fall Reunion on Columbus day weekends. After the end of its operating lease, the East Broad Top Preservation Association had raised enough money to purchase some portions of the EBT. On June 3, 2013, it was announced that the East Broad Top Preservation Association had purchased the first part of the East Broad Top Railroad. In two separate transactions, the Association purchased
3800-511: The M-1, a motorcar (doodlebug) based on scaled-down J. G. Brill and Company plans built by the EBT in 1927. The majority of rolling stock that operated on the railroad in its later coal-hauling years remains on the property in varying condition, including over a dozen flatcars, several boxcars and well over 150 hoppers. Tourist trains used original EBT passenger equipment, as well as converted EBT freight cars. The original railroad maintenance shops have
3900-472: The Saltillo station and water tower. In December 2021 the railroad received a state Redevelopment Assistance Capital Program grant for $ 1.1M USD. The funds will be used to restore and reopen the main line to Saltillo and other capital improvements. In May 2022 the railroad took the first steps toward reopening the line from Rockhill Furnace south to Saltillo by cutting down growth and repairing drainage along
4000-643: The absence of reinforcement, its tensile strength was far lower than modern reinforced concrete , and its mode of application also differed: Modern structural concrete differs from Roman concrete in two important details. First, its mix consistency is fluid and homogeneous, allowing it to be poured into forms rather than requiring hand-layering together with the placement of aggregate, which, in Roman practice, often consisted of rubble . Second, integral reinforcing steel gives modern concrete assemblies great strength in tension, whereas Roman concrete could depend only upon
4100-430: The annual fall spectaculars. There were plans during this era to bring other portions of the East Broad Top back to service, most notably with the 1990 National Park Service proposal, but funding and inner politics prevented this, and operational trackage was never further extended. As the years went on, the condition of the running locomotives deteriorated, and both rising costs and stricter operational standards after
East Broad Top Railroad and Coal Company - Misplaced Pages Continue
4200-541: The best candidates for return to operation. Nos. 14 and 16 were selected to be the first to be restored and were abated of asbestos and restoration work begun. Stall #8 of the Rockhill Roundhouse was rehabilitated and converted into a restoration facility for the steam locomotives. Woodford Brothers (who performed structural repairs of the Blacksmith Shop during the closure) were contracted to perform
4300-409: The building and water tank that had once served the Saltillo station. The line further south to Robertsdale is blocked by two 1874-built tunnels that require significant repair work. A LIDAR equipped drone was used to survey their condition for rehabilitation planning. At Robertsdale, which is land-locked from the operating portion of the railroad, the first section of a hard-paved walking path to
4400-630: The cisterns secret as these enabled the Nabataeans to thrive in the desert. Some of these structures survive to this day. In the Ancient Egyptian and later Roman eras, builders discovered that adding volcanic ash to lime allowed the mix to set underwater. They discovered the pozzolanic reaction . The Romans used concrete extensively from 300 BC to AD 476. During the Roman Empire, Roman concrete (or opus caementicium )
4500-661: The coal-mining company was sold for scrap to the Kovalchick Salvage Corporation. Nick Kovalchick, president of Kovalchick Salvage, elected not to scrap the railroad right away, instead letting it sit in place. In 1960, the twin boroughs of Orbisonia and Rockhill Furnace —the latter being the operating hub for the railroad—celebrated their Bicentennial and asked Kovalchick to put a train out for display. Doing them one better, he rehabilitated four miles of track and two locomotives and operated tourist train rides for several months that summer. The new attraction
4600-526: The concrete at the time of batching/mixing. (See § Production below.) The common types of admixtures are as follows: Inorganic materials that have pozzolanic or latent hydraulic properties, these very fine-grained materials are added to the concrete mix to improve the properties of concrete (mineral admixtures), or as a replacement for Portland cement (blended cements). Products which incorporate limestone , fly ash , blast furnace slag , and other useful materials with pozzolanic properties into
4700-399: The concrete can cause the initially placed material to begin to set before the next batch is added on top. This creates a horizontal plane of weakness called a cold joint between the two batches. Once the mix is where it should be, the curing process must be controlled to ensure that the concrete attains the desired attributes. During concrete preparation, various technical details may affect
4800-461: The concrete quality. Central mix plants must be close to the work site where the concrete will be used, since hydration begins at the plant. A concrete plant consists of large hoppers for storage of various ingredients like cement, storage for bulk ingredients like aggregate and water, mechanisms for the addition of various additives and amendments, machinery to accurately weigh, move, and mix some or all of those ingredients, and facilities to dispense
4900-528: The crack from spreading. The widespread use of concrete in many Roman structures ensured that many survive to the present day. The Baths of Caracalla in Rome are just one example. Many Roman aqueducts and bridges, such as the magnificent Pont du Gard in southern France, have masonry cladding on a concrete core, as does the dome of the Pantheon . After the Roman Empire, the use of burned lime and pozzolana
5000-665: The dual-gauge Mount Union yard. Switcher #6 was sold in 1975 to the Whitewater Valley Railroad . In 2024, switcher #3, owned by the EBTPA, was sold and transported to the Red Bay Museum in Red Bay, Alabama . The Rockhill Trolley Museum, operated by Railways to Yesterday, adjoins the railroad and offers 3-mile (4.8 km) round-trip trolley rides during the tourist season on the former Shade Gap Branch of
5100-431: The finished product. Construction aggregates consist of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone , or granite , along with finer materials such as sand . Cement paste, most commonly made of Portland cement , is the most prevalent kind of concrete binder. For cementitious binders, water is mixed with the dry cement powder and aggregate, which produces
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#17327906985635200-487: The first time since 1956 that EBT rolling stock returned to the site of its headquarters during its days as a coal carrier. In February 2021 workers in the carpentry shop found five cases of century-old dynamite. In the nineteenth and early twentieth centuries railroads commonly used explosives to clear debris. Local and federal agencies safely burned off the explosives. In October the Friends group announced plans to rebuild
5300-506: The former coal mine sites once served by the EBT opened in October 2024. The path will eventually extend about one mile and include interpretive signage. Rail bikes and speeders now operate over two miles of EBT track to the town of Woodvale. In August the Friends group began preparing the foundation of the long-demolished engine house for the construction of a replica building. Steam locomotive No. 16, which had been out of service since 1956,
5400-681: The gaps to make up a solid mass in situ . The word concrete comes from the Latin word " concretus " (meaning compact or condensed), the perfect passive participle of " concrescere ", from " con -" (together) and " crescere " (to grow). Concrete floors were found in the royal palace of Tiryns , Greece, which dates roughly to 1400 to 1200 BC. Lime mortars were used in Greece, such as in Crete and Cyprus, in 800 BC. The Assyrian Jerwan Aqueduct (688 BC) made use of waterproof concrete . Concrete
5500-508: The historic railroad, except October and December, as well as a special work week per year. FEBT volunteers restore buildings, machinery, repair track and rolling stock, provide tours, and help maintain the premises. Since 2002 substantial restoration has occurred on more than half the core maintenance shop complex. Several other buildings have received moderate to extensive restoration. Five pieces of rolling stock have been returned to operation with three more in progress. Six pieces of machinery in
5600-601: The industries it served in the surrounding area. FEBT is also nearing completion on the restoration of the RI&;C Co. owned Robertsdale Post Office building, which will eventually house the museum's exhibits, while the station will be fully restored to its period appearance. The Robertsdale Historic District and Woodvale Historic District were listed on the National Register of Historic Places in 1992. 3 ft gauge railways Three foot gauge railways have
5700-554: The interlinking of the silicates and aluminate components as well as their bonding to sand and gravel particles to form a solid mass. One illustrative conversion is the hydration of tricalcium silicate: The hydration (curing) of cement is irreversible. Fine and coarse aggregates make up the bulk of a concrete mixture. Sand , natural gravel, and crushed stone are used mainly for this purpose. Recycled aggregates (from construction, demolition, and excavation waste) are increasingly used as partial replacements for natural aggregates, while
5800-470: The late 1990s the relationship was on the mend with cooperative projects and starting in 2002 FEBT volunteers again began restoration work in Rockhill Furnace. This work continues today and has grown immensely in scope and depth during that time. As of late 2022 the Foundation has three full-time paid track crew members. On weekends the volunteer FEBT Rockhill Restoration Crew performs restoration work on
5900-454: The line. In May and June 2020 the restoration efforts encountered setbacks from an act of arson and a bridge was damaged by an over-height vehicle. The East Broad Top reopened for limited operations in May 2021, and officially reopened for its first full season in May 2022. EBT No. 16 returned to steam in early February, 2023. In the years following the EBT's opening as a tourist hauler, many of
6000-426: The maintenance shops have been restored to operation and some are being used to make parts for other restoration projects. Seven pieces of track have received work. The crew also works on restoration projects on parts of the railroad outside Rockhill Furnace. With the purchase of the railroad by the EBT Foundation, which has an excellent working relationship with FEBT, restoration work is being greatly accelerated. EBTF
6100-406: The making of mortar. In an English translation from 1397, it reads "lyme ... is a stone brent; by medlynge thereof with sonde and water sement is made". From the 14th century, the quality of mortar was again excellent, but only from the 17th century was pozzolana commonly added. The Canal du Midi was built using concrete in 1670. Perhaps the greatest step forward in the modern use of concrete
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#17327906985636200-531: The material. Mineral admixtures use recycled materials as concrete ingredients. Conspicuous materials include fly ash , a by-product of coal-fired power plants ; ground granulated blast furnace slag , a by-product of steelmaking ; and silica fume , a by-product of industrial electric arc furnaces . Structures employing Portland cement concrete usually include steel reinforcement because this type of concrete can be formulated with high compressive strength , but always has lower tensile strength . Therefore, it
6300-419: The mix, are being tested and used. These developments are ever growing in relevance to minimize the impacts caused by cement use, notorious for being one of the largest producers (at about 5 to 10%) of global greenhouse gas emissions . The use of alternative materials also is capable of lowering costs, improving concrete properties, and recycling wastes, the latest being relevant for circular economy aspects of
6400-478: The mixed concrete, often to a concrete mixer truck. Modern concrete is usually prepared as a viscous fluid, so that it may be poured into forms. The forms are containers that define the desired shape. Concrete formwork can be prepared in several ways, such as slip forming and steel plate construction . Alternatively, concrete can be mixed into dryer, non-fluid forms and used in factory settings to manufacture precast concrete products. Interruption in pouring
6500-441: The mixing of cement and water into a paste before combining these materials with aggregates can increase the compressive strength of the resulting concrete. The paste is generally mixed in a high-speed , shear-type mixer at a w/c (water to cement ratio) of 0.30 to 0.45 by mass. The cement paste premix may include admixtures such as accelerators or retarders, superplasticizers , pigments , or silica fume . The premixed paste
6600-441: The mixture to improve the physical properties of the wet mix, delay or accelerate the curing time, or otherwise change the finished material. Most concrete is poured with reinforcing materials (such as steel rebar ) embedded to provide tensile strength , yielding reinforced concrete . In the past, lime -based cement binders, such as lime putty, were often used but sometimes with other hydraulic cements , (water resistant) such as
6700-653: The old PRR/Conrail spur from the Norfolk Southern mainline to the northern end of the EBT yard from Kovlachick Salvage, and the EBT Mount Union yard from the Conrail Spur tie-in to the US 522 crossing from the East Broad Top Railroad and Coal Company EBTPA subsequently purchased the line from Mount Union to Aughwick. After these initial purchases, the EBTPA was unable to fund further purchases of portions of
6800-521: The oldest railroad roundhouses in the US still in operation, was built in 1882. A coal cleaning plant and a full maintenance shops complex were also built, bridges were upgraded from iron and wood to steel and concrete, wood rolling stock was replaced by steel, and modern high-powered steam locomotives were bought from the Baldwin Locomotive Works of Philadelphia. In the post-WWII years most railroads converted to diesel motive power but
6900-506: The properties or increase the performance envelope of the mix. Design-mix concrete can have very broad specifications that cannot be met with more basic nominal mixes, but the involvement of the engineer often increases the cost of the concrete mix. Concrete mixes are primarily divided into nominal mix, standard mix and design mix. Nominal mix ratios are given in volume of Cement : Sand : Aggregate {\displaystyle {\text{Cement : Sand : Aggregate}}} . Nominal mixes are
7000-468: The quality and nature of the product. Design mix ratios are decided by an engineer after analyzing the properties of the specific ingredients being used. Instead of using a 'nominal mix' of 1 part cement, 2 parts sand, and 4 parts aggregate (the second example from above), a civil engineer will custom-design a concrete mix to exactly meet the requirements of the site and conditions, setting material ratios and often designing an admixture package to fine-tune
7100-466: The railroad came to subsist on coal traffic for about 90% of its revenue. Large plants for the manufacture of silica brick were developed at Mount Union around the turn of the 20th century, and these became major customers for coal and also for ganister rock, which was quarried at multiple points along the railroad. At Mount Union the yard consisted of dual gauge trackage. EBT had an enginehouse for two standard gauge locomotives which handled switching between
7200-456: The railroad in its last years as a coal hauler are still on site, and some were used for the excursion trains. Other original equipment includes a 4 ft 8 + 1 ⁄ 2 in ( 1,435 mm ) standard gauge switcher steam locomotive (non-operational), operating track-gang cars, the M-3 motorcar (built from scratch by the EBT with an engine and transmission from an automobile), and
7300-576: The railroad to the EBTF did not include portions of the railroad previously purchased by the East Broad Top Preservation Association. The two non-profits are separate and unaffiliated. It did not include EBT standard gauge steam locomotive #3 then stored at the Mount Union yard. Immediately after the announcement, the EBTF began several parallel projects at the railroad to prepare for resumption of operations. All six narrow-gauge steam locomotives were thoroughly evaluated to determine their condition and which were
7400-472: The railroad transitioned to haul most of the coal to Mount Union to be processed and transferred to the Pennsylvania Railroad . The railroad also carried substantial amounts of ganister (orthoquartzite rock, used for furnace lining), lumber and passengers with some agricultural goods, concrete , road tar and general freight. As the iron industry in the region faded in the early 1900s,
7500-401: The railroad was to haul semi- bituminous coal from the mines on the east side of the remote Broad Top Mountain plateau. In its first few decades, the railroad hauled most of the coal to Rockhill to be coked and used in iron production in the furnaces of the Rockhill Iron and Coal Company, its sister company. It then hauled the pig iron from the furnace. Shortly after the turn of the 20th century,
7600-475: The railroad. Public tours were increasingly offered on selected summer days as the closure continued. The neighboring Rockhill Trolley Museum continued to operate its regular summer schedule and special events, as well as their portion of the Fall Spectaculars during Columbus Day weekend in October. On Valentine's Day, 2020, a press conference was held in Rockhill announcing that a new non-profit,
7700-415: The restored trackage just south of Rockhill Furnace. During this era of operations, four of the six Mikados were in service: #12, #14, #15 and #17. The heavier locomotives #16 and #18 never operated during this era, due to finances, differing opinions, and concerns about the effect their weight would have on the track; #17, of very similar size to #16 and #18, was used sparingly, typically only running during
7800-525: The right-of-way. Deteriorated structures at the Colgate picnic grove, at the railroad's wye track on the old Clay spur, were demolished. New pavilions, restrooms, and a boarding platform were opened for the 2023 season. During 2023-2024 the right of way was rebuilt and opened up to Pennsylvania Route 475 . In March 2024 rail was being re-laid south of PA 475. Heritage service opened on the restored 1.3-mile section in October 2024. As of late 2024, track work
7900-703: The season and operating days of the week. The original three-year lease expired in April 2012, and Kovalchick Salvage and EBTPA were unable to reach an agreement to continue operations. As such the lease was terminated. From 1960 until 2011 the line operated as a heritage railway , with trains pulled by 3 ft narrow gauge 2-8-2 steam locomotives . Vintage diesels operated as backup power. Excursions generally ran May through October. Special events and holidays trains ran in November and December. The rides were 10-mile (16 km) round trips and took about an hour. The EBT annual Fall Spectacular, when all operating equipment
8000-570: The standard and narrow gauge sides of the coal cleaning plant. The EBT maintained an office in Philadelphia, PA. An 1893 timetable lists their executive offices at 320 Walnut St., then the main commercial area of the city. The city's business center migrated west and by 1939 the EBT's office was at 1421 Chestnut St. EBT was generally profitable from the 1880s through the 1940s and was able to modernize its infrastructure far more than other narrow gauge railroads. The railroad's roundhouse , one of
8100-411: The strength of the concrete bonding to resist tension. The long-term durability of Roman concrete structures has been found to be due to its use of pyroclastic (volcanic) rock and ash, whereby the crystallization of strätlingite (a specific and complex calcium aluminosilicate hydrate) and the coalescence of this and similar calcium–aluminium-silicate–hydrate cementing binders helped give the concrete
8200-407: The structures along the disused portion of the railroad fell into disrepair and were lost to neglect or arson. Maintenance on the original railroad maintenance shops and other buildings at Rockhill Furnace and on unused equipment was neglected as employees focused the limited manpower on operating the train and maintaining core facilities. As a result, historic fabric outside the core tourist operations
8300-497: The surface of concrete for a decorative "exposed aggregate" finish, popular among landscape designers. Admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes. Admixtures are defined as additions "made as the concrete mix is being prepared". The most common admixtures are retarders and accelerators. In normal use, admixture dosages are less than 5% by mass of cement and are added to
8400-535: The surfaces of the aggregate together, and is typically the most expensive component. Thus, variation in sizes of the aggregate reduces the cost of concrete. The aggregate is nearly always stronger than the binder, so its use does not negatively affect the strength of the concrete. Redistribution of aggregates after compaction often creates non-homogeneity due to the influence of vibration. This can lead to strength gradients. Decorative stones such as quartzite , small river stones or crushed glass are sometimes added to
8500-655: The various ingredients used to produce a given quantity of concrete, the cement is the most energetically expensive. Even complex and efficient kilns require 3.3 to 3.6 gigajoules of energy to produce a ton of clinker and then grind it into cement . Many kilns can be fueled with difficult-to-dispose-of wastes, the most common being used tires. The extremely high temperatures and long periods of time at those temperatures allows cement kilns to efficiently and completely burn even difficult-to-use fuels. The five major compounds of calcium silicates and aluminates comprising Portland cement range from 5 to 50% in weight. Combining water with
8600-439: The water content or adding chemical admixtures increases concrete workability. Excessive water leads to increased bleeding or segregation of aggregates (when the cement and aggregates start to separate), with the resulting concrete having reduced quality. Changes in gradation can also affect workability of the concrete, although a wide range of gradation can be used for various applications. An undesirable gradation can mean using
8700-527: The water through a process called concrete hydration that hardens it over several hours to form a hard matrix that binds the materials together into a durable stone-like material that has many uses. This time allows concrete to not only be cast in forms, but also to have a variety of tooled processes performed. The hydration process is exothermic , which means ambient temperature plays a significant role in how long it takes concrete to set. Often, additives (such as pozzolans or superplasticizers ) are included in
8800-524: Was Smeaton's Tower , built by British engineer John Smeaton in Devon , England, between 1756 and 1759. This third Eddystone Lighthouse pioneered the use of hydraulic lime in concrete, using pebbles and powdered brick as aggregate. A method for producing Portland cement was developed in England and patented by Joseph Aspdin in 1824. Aspdin chose the name for its similarity to Portland stone , which
8900-626: Was built largely of concrete, and the Pantheon has the world's largest unreinforced concrete dome. Concrete, as the Romans knew it, was a new and revolutionary material. Laid in the shape of arches , vaults and domes , it quickly hardened into a rigid mass, free from many of the internal thrusts and strains that troubled the builders of similar structures in stone or brick. Modern tests show that opus caementicium had as much compressive strength as modern Portland-cement concrete (c. 200 kg/cm [20 MPa; 2,800 psi]). However, due to
9000-565: Was designated a National Historic Landmark in 1964 and added to the National Register of Historic Places in 1966. The railroad was added in 1996 to the National Trust for Historic Preservation 's list of America's Most Endangered Places . The East Broad Top Railroad and Coal Company was chartered in 1856. Due to financial constraints and the American Civil War , the railroad was not built by its original charterers, but
9100-463: Was fired up in July 2022 in preparation for its entry into excursion service. It was operated during the 2023 season but the following April was withdrawn from service when a crack was found in the center of one of its drive wheels. Following 8 months of repair work and successful test runs, No. 16 returned to service on August 30, 2024. No. 15 is selected as the next locomotive to be restored although there
9200-602: Was greatly reduced. Low kiln temperatures in the burning of lime, lack of pozzolana, and poor mixing all contributed to a decline in the quality of concrete and mortar. From the 11th century, the increased use of stone in church and castle construction led to an increased demand for mortar. Quality began to improve in the 12th century through better grinding and sieving. Medieval lime mortars and concretes were non-hydraulic and were used for binding masonry, "hearting" (binding rubble masonry cores) and foundations. Bartholomaeus Anglicus in his De proprietatibus rerum (1240) describes
9300-543: Was in use, was held on the Saturday and Sunday of Columbus Day weekend in October. There were also local events such as Community Appreciation Day. The train stopped at Colgate Grove, a picnic grove at the far end of the operable excursion trackage. The train was turned on a wye for the return trip. The historic railroad maintenance shops were usually open for tours when trains were running, and for group tours by arrangement. Speeder, handcar, and M-3 rides were often available on
9400-452: Was made from quicklime , pozzolana and an aggregate of pumice . Its widespread use in many Roman structures , a key event in the history of architecture termed the Roman architectural revolution , freed Roman construction from the restrictions of stone and brick materials. It enabled revolutionary new designs in terms of both structural complexity and dimension. The Colosseum in Rome
9500-498: Was pioneered by the Nabatean traders who occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan from the 4th century BC. They discovered the advantages of hydraulic lime , with some self-cementing properties, by 700 BC. They built kilns to supply mortar for the construction of rubble masonry houses, concrete floors, and underground waterproof cisterns . They kept
9600-572: Was quarried on the Isle of Portland in Dorset , England. His son William continued developments into the 1840s, earning him recognition for the development of "modern" Portland cement. Reinforced concrete was invented in 1849 by Joseph Monier . and the first reinforced concrete house was built by François Coignet in 1853. The first concrete reinforced bridge was designed and built by Joseph Monier in 1875. Prestressed concrete and post-tensioned concrete were pioneered by Eugène Freyssinet ,
9700-558: Was severely threatened. In 1983, the non-profit Friends of the East Broad Top (FEBT) was organized to preserve and restore the East Broad Top. While initially there was a good working relationship between the EBT and the FEBT, including two and a half years of restoration work at Rockhill Furnace, a series of events in 1985 led to friction and distrust between the two entities. At that time, FEBT re-focused on restoration at Robertsdale where it purchased or leased two historic EBT/RI&C Structures, and on former EBT combine #16 it had leased. In
9800-523: Was so successful that the ride, extended to five miles (8.0 km), opened as a regular tourist operation in 1961. The railroad operated tourist trains every summer through 2011. From 1960 to 2008 the trains were operated by the EBT under Kovalchick Salvage. From 1956 until 2020, the majority of the railroad was still owned by Kovalchick Salvage. It was overseen by Nick Kovalchick from 1956 to 1977 and by Nick's son, Joe, and his wife, Judy after 1977. From May 2009 until December 2011, trains were operated under
9900-589: Was underway between the Jordan road underpass and the Pennsylvania Route 994 Pogue Road crossing. Further south, crews have cut down decades of overgrowth and cleared the right of way as far as Pogue. The extension of steam heritage service to Three Springs and Saltillo is anticipated by late 2025 or early 2026. This work requires some masonry repair work on the Pogue Bridge and reconstruction of
10000-625: Was used for construction in many ancient structures. Mayan concrete at the ruins of Uxmal (AD 850–925) is referenced in Incidents of Travel in the Yucatán by John L. Stephens . "The roof is flat and had been covered with cement". "The floors were cement, in some places hard, but, by long exposure, broken, and now crumbling under the feet." "But throughout the wall was solid, and consisting of large stones imbedded in mortar, almost as hard as rock." Small-scale production of concrete-like materials
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