The ALCO RSD-4 was a diesel-electric locomotive of the road switcher type rated at 1,600 horsepower, that rode on three-axle trucks, having a C-C wheel arrangement. Used in much the same manner as its four-axle counterpart, the ALCO RS-3, though the six-motor design allowed better tractive effort at lower speeds. Due to the inadequate capacity of the main generator, this model was superseded in production by the ALCO RSD-5 The only ALCO RSD-4 that has survived is Kennecott Copper Corporation #201; as of 2007, it resides in restored condition at the Northwest Railway Museum in Snoqualmie, wearing a coat of bright orange paint. Dorin, Patrick C.. Chicago and North Western Power. Burbank, California: Superior Publishing. P. 141. ISBN 0-87564-715-4. Pinkepank, Jerry A.. The Second Diesel Spotter's Guide. Milwaukee, Wisconsin: Kalmbach Publishing. P. 247. ISBN 978-0-89024-026-7
Minimum railway curve radius
The minimum railway curve radius is the shortest allowable design radius for the center line of railway tracks under a particular set of conditions. It has an important bearing on constructions costs and operating costs and, in combination with superelevation in the case of train tracks, determines the maximum safe speed of a curve. Minimum radius of curve is one parameter in the design of railway vehicles as well as trams. Monorails and guideways are subject to minimum radii; the first proper railway was the Liverpool and Manchester Railway, which opened in 1830. Like the tram roads that had preceded it over a hundred years, the L&M had gentle curves and gradients. Among other reasons for the gentle curves were the lack of strength of the track, which might have overturned if the curves were too sharp causing derailments. There was no signalling at this time, so drivers had to be able to see ahead to avoid collisions with other trains on the line; the gentler the curves, the longer the visibility.
The earliest rails were made in short lengths of wrought iron, which does not bend like steel rails introduced in the 1850s. Minimum curve radii for railroads are governed by the speed operated and by the mechanical ability of the rolling stock to adjust to the curvature. In North America, equipment for unlimited interchange between railroad companies are built to accommodate 288-foot radius, but 410-foot radius is used as a minimum, as some freight cars are handled by special agreement between railroads that cannot take the sharper curvature. For handling of long freight trains, a minimum 574-foot radius is preferred; the sharpest curves tend to be on the narrowest of narrow gauge railways, where everything is proportionately smaller. As the need for more powerful locomotives grew, the need for more driving wheels on a longer, fixed wheelbase grew too, but long wheel bases are unfriendly to sharp curves. Various types of articulated locomotives were devised to avoid having to operate multiple locomotives with multiple crews.
More recent diesel and electric locomotives do not have a wheelbase problem and can be operated in multiple with a single crew. The Tasmanian Government Railways K class was 610 mm gauge 99 ft radius curves Example Garratt 1,000 mm gauge 25 kg/m rails Main line radius - 175 m Siding radius - 84 m 0-4-0 GER Class 209 1,435 mm Not all couplers can handle sharp curves; this is true of the European buffer and chain couplers, where the buffers extend the profile of the railcar body. For a line with maximum speed 60 km/h, buffer-and-chain couplings increase the minimum radius to around 150 m; as narrow gauge railways and metros do not interchange with mainline railroads, instances of these types of railroad in Europe use bufferless central couplers and build to a tighter standard. A long heavy freight train those with wagons of mixed loading, may struggle on sharp curves, as the drawgear forces may pull intermediate wagons off the rails. Common solutions include: marshalling light and empty wagons at rear of train intermediate locomotives, including remotely controlled ones.
Easing curves reduced. More, shorter trains. Equalizing wagon loading better driver training driving controls, and c2013 Electronically Controlled Pneumatic brakes. A similar problem occurs with harsh changes in gradients; as a heavy train goes round a bend at speed, the reactive centrifugal force can cause negative effects: passengers and cargo may feel unpleasant forces, the inside and outside rails will wear unequally, insufficiently anchored track may move. To counter this, a cant is used. Ideally the train should be tilted such that resultant force acts straight "down" through the bottom of the train, so the wheels, track and passengers feel little or no sideways force; some trains are capable of tilting to enhance this effect for passenger comfort. Because freight and passenger trains tend to move at different speeds, a cant cannot be ideal for both types of rail traffic; the relationship between speed and tilt can be calculated mathematically. We start with the formula for a balancing centripetal force: θ is the angle by which the train is tilted due to the cant, r is the curve radius in meters, v is the speed in meters per second, g is the standard gravity equal to 9.80665 m/s²: tan θ = v 2 g r Rearranging for r gives: r = v 2 g tan θ Geometrically, tan θ can be expressed in terms of the track gauge G, the cant ha and cant deficiency hb, all in millimeters: tan θ ≈ sin θ = h a + h b G This approximation for tan θ gives: r = v 2 g h a + h b G
ALCO S-2 and S-4
The ALCO S2 and S4 were 1,000 horsepower diesel electric switchers produced by ALCO and Canadian licensee Montreal Locomotive Works. The two locomotives differed only in trucks, with the S-2 using ALCO "Blunt" trucks, the S-4 using AAR type A switcher trucks. Both were powered by ALCO 539 6-cylinder diesels; the S-2 was built between August 1940 and June 1950, with a total of 1502 completed, while the S-4 was constructed between June 1949 and August 1957 with total sales of 797. Canadian production of the S-4 started more than a year before U S production of the S-4. ALCO did not start building the S-4 until August 1950. A modified version, the S-7, was built by MLW only; the exterior of the locomotives were styled by an Alco engineer, Ray Patten, using curves in a mild application of Art Deco principles. The S-2 and S-4 are distinguishable externally from the similar S-1 and S-3 660 hp switchers in that they have a larger exhaust stack with an oblong base and a larger radiator shutter area on the nose sides.
The S-1/S-3 radiator shutter area is taller than it is wide, while the S-2/S-4 radiator area is wider. The larger stack is due to turbocharging; the carbody and cab of late S-2s are nearly indistinguishable from those of S-4s. Hence, a truck swap can cause many to misidentify a unit. A few S4s are still in service on shortline railroads around the United States. Several more are preserved in Canadian railroad museums. An S-2, of D&RGW heritage, survives on the Big South Fork Scenic Railway, as number 102, it was purchased in February 1964 for the Kentucky and Tennessee Railway, is in operable condition in Stearns, Kentucky. This was one of the diesels that replaced Southern 2-8-2 #4501 on the K&T. SP1474 is in operation, in rotation, at the Orange Empire Railway Museum in Perris, CA, pulling a tourist train on weekends. Western Pacific 563, one of 2 S4s purchased by that railroad, is today preserved at the Western Pacific Railroad Museum at Portola, California. Fore River Transportation has at least one S-4 in a derelict state being used for parts.
New York and Western Railway S2 #206 sits cosmetically restored at Maywood Station in Maywood, New Jersey. The Cooperstown and Charlotte Valley Railroad operates a pair of restored ex-Canadian National units. S4 #3051 and S7 #3052 are both in regular tourist passenger and maintenance of way service between Milford and Cooperstown, NY. Muskogee, Oklahoma at the Three Rivers Museum a S-2 #63-138 sits outside in the back of the Midland Valley Station; the Houston Railroad Museum in Houston, Texas have two S-2's. Conrad Yelvington Distributors, an aggregate supplier in Orlando, owns a former Chesapeake & Ohio S-2, now numbered 224. Though not used as as their EMD SW9 number 2112, the unit is operational; the Florida Railroad Museum in Parrish owns ex-Conrad Yelvington ALCO S2 #251, used as a backup engine on their weekend train rides. Louisville & Nashville rebuilt many of their Alco switchers with 12-567 EMD prime movers in an effort to standardize their switching fleet. One of these, S4 #2326 survives at Gerdau Ameristeel in Cartersville, GA.
Ameristeel donated the locomotive to the Southeastern Railway Museum at Duluth, GA. The Oil Creek and Titusville Railroad operates # 85 on its tourist/freight railroad; the Virginia & Truckee Railroad acquired an S-4 from PPL Montana in 2010. The locomotive is in operable condition & being repainted to the railroad's diesel colors. Class III railroad Toledo, Lake Erie, Western owns four ALCO S-2 and S-4s. TLEW 62, a S-2 purchased in 2012, ex. Delray Cement 62, TLEW 112, a S-2, part of the original TLEW roster, now reduced to a parts unit as of 2010, TLEW 5109, a S-4, the only operating ALCO on the line currently. 5109 was repainted into its original Chesapeake and Ohio colors in September 2013. TLEW 5109's horn was stolen during the repainting process. TLEW 9752, a S-4 of Penn Central and Pittsburgh & Lake Erie heritage, was not used much, was scrapped for parts in October 2010. Heritage Cooperative in Mechanicsburg, Ohio, is the latest in a string of owners for the former Baltimore & Ohio 9040, an operating S-2 that retains her second B&O number.
She was built as B&O 496 in 1945. The North Alabama Railroad Museum in Huntsville, Alabama runs an S-2 in regular tourist excursions and Chase #213, it owns another S-2, Mercury & Chase #484, temporarily out of service due to cylinder repair, but returned to service with #213 in 2018. They have ex-Santa Fe #1534, an S-4. San Francisco Bay Railroad, the short-line railroad for the Port of San Francisco, operates the #23 and #25 Alco S-2's from the San Francisco Belt Line Railroad. In the mid-1960s, Hamersley Iron purchased an S-2 for use in the Pilbara region of Western Australia; the Beech Mountain Railroad at Alexander, in North Central West Virginia Rosters an S-2, numbered 113 and an S-4, numbered 115 for their 8 mile long coal hauling line. Both were built new for Chemical Company. ADMX "E'Ville" 1 was on static display in Evansville, near CSX Transportation's Howell terminal. ADM scrapped it in early Fall of 2017; the MD&W short line railroad in northern Minnesota uses S-2s to help former Boise Cascade now just Boise paper mill set out goods to the former Burlington Northern main line railroad now Canadian National, within the last 10 years MD&W has purchased an EMD SW-10 to help switching duties List of ALCO diesel locomotives List of MLW diesel locomotives Dorin, Patrick C..
Chicago and North Western Power. Burbank, California: Superior Publishing. P
The Diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel, injected into the combustion chamber, is caused by the elevated temperature of the air in the cylinder due to the mechanical compression. Diesel engines work by compressing only the air; this increases the air temperature inside the cylinder to such a high degree that atomised Diesel fuel injected into the combustion chamber ignites spontaneously. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven; the process of mixing air and fuel happens entirely during combustion, the oxygen diffuses into the flame, which means that the Diesel engine operates with a diffusion flame. The torque a Diesel engine produces is controlled by manipulating the air ratio; the Diesel engine has the highest thermal efficiency of any practical internal or external combustion engine due to its high expansion ratio and inherent lean burn which enables heat dissipation by the excess air.
A small efficiency loss is avoided compared with two-stroke non-direct-injection gasoline engines since unburned fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed Diesel engines can reach effective efficiencies of up to 55%. Diesel engines may be designed as either four-stroke cycles, they were used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in ships. Use in locomotives, heavy equipment and electricity generation plants followed later. In the 1930s, they began to be used in a few automobiles. Since the 1970s, the use of Diesel engines in larger on-road and off-road vehicles in the US has increased. According to Konrad Reif, the EU average for Diesel cars accounts for 50% of the total newly registered; the world's largest Diesel engines put in service are 14-cylinder, two-stroke watercraft Diesel engines. In 1878, Rudolf Diesel, a student at the "Polytechnikum" in Munich, attended the lectures of Carl von Linde.
Linde explained that steam engines are capable of converting just 6-10 % of the heat energy into work, but that the Carnot cycle allows conversion of all the heat energy into work by means of isothermal change in condition. According to Diesel, this ignited the idea of creating a machine that could work on the Carnot cycle. After several years of working on his ideas, Diesel published them in 1893 in the essay Theory and Construction of a Rational Heat Motor. Diesel was criticised for his essay, but only few found the mistake that he made. Diesel's idea was to compress the air so that the temperature of the air would exceed that of combustion. However, such an engine could never perform any usable work. In his 1892 US patent #542846 Diesel describes the compression required for his cycle: "pure atmospheric air is compressed, according to curve 1 2, to such a degree that, before ignition or combustion takes place, the highest pressure of the diagram and the highest temperature are obtained-that is to say, the temperature at which the subsequent combustion has to take place, not the burning or igniting point.
To make this more clear, let it be assumed that the subsequent combustion shall take place at a temperature of 700°. In that case the initial pressure must be sixty-four atmospheres, or for 800° centigrade the pressure must be ninety atmospheres, so on. Into the air thus compressed is gradually introduced from the exterior finely divided fuel, which ignites on introduction, since the air is at a temperature far above the igniting-point of the fuel; the characteristic features of the cycle according to my present invention are therefore, increase of pressure and temperature up to the maximum, not by combustion, but prior to combustion by mechanical compression of air, there upon the subsequent performance of work without increase of pressure and temperature by gradual combustion during a prescribed part of the stroke determined by the cut-oil". By June 1893, Diesel had realised his original cycle would not work and he adopted the constant pressure cycle. Diesel describes the cycle in his 1895 patent application.
Notice that there is no longer a mention of compression temperatures exceeding the temperature of combustion. Now it is stated that the compression must be sufficient to trigger ignition. "1. In an internal-combustion engine, the combination of a cylinder and piston constructed and arranged to compress air to a degree producing a temperature above the igniting-point of the fuel, a supply for compressed air or gas. See US patent # 608845 filed 1895 / granted 1898In 1892, Diesel received patents in Germany, the United Kingdom and the United States for "Method of and Apparatus for Converting Heat into Work". In 1894 and 1895, he filed patents and addenda in various
Southern California Railway Museum
The Southern California Railway Museum known as the Orange Empire Railway Museum, at 2201 South "A" Street in Perris, California, is a railroad museum founded in 1956 at the Pinacate Station as the "Orange Empire Trolley Museum." The museum operates a heritage railroad on the museum grounds. The collection focuses on Southern California's railroad history, it houses the largest collection of Pacific Electric Railway rolling stock in the world, much of it rescued from scrapyards after the discontinuation of their passenger operations. Two early Los Angeles 3 ft 6 in narrow gauge streetcars from the Los Angeles Railway or standard gauge streetcars from the Pacific Electric Railway run each weekend on the one-half-mile long, dual gauge Loop Line. A passenger-carrying steam, diesel or electric powered freight train with open gondolas fitted with benches and at least two cabooses runs on the 1.5-mile long, standard gauge mainline, once a part of the transcontinental main line of the Atchison and Santa Fe Railway.
Its main line stretches from south of the museum northward towards the junction with the BNSF Railway, where the historic Perris Depot on State Route 74 stands. The BNSF Railway spur is in active use, but the museum track onto the spur is severed due to Metrolink service, meaning that no museum trains can access the Perris Depot. A Pacific Electric interurban "Red Car" operates on the mainline on selected weekends, but the line electrification ends a block south of the depot. Streetcars and locomotives are selected on a rotating basis; the museum maintains a steam locomotive in operating condition and its use is scheduled for each third weekend, September through May, certain special events and major holidays. Admission to the SCRM and parking are free except for special events, but a ticket must be purchased to ride on the museum railway; the ticket is valid for unlimited rides on streetcars. Tours of the grounds, static exhibits and shops can be self-guided or with a docent. A picnic area is located near the main entrance as is an interactive railroad "signal garden."
Built between 2000 and 2001 and utilizing a combination of standard railroad signal relays and custom microprocessor controls, the garden's first phase included: Two restored Magnetic Flagman grade crossing signals, both upper- and lower-quadrant Safetran V20 tri-light block signal, a new signal installed on the Southern Pacific Coastal Route and removed from service for standardization purposes by its successor, the Union Pacific Railroad Union Switch and Signal motorcar indicators which were miniature semaphores designed to warn maintenance crews of oncoming trains Union Switch and Signal motorcar indicator as used by the ATSF. 1910. This is a large, bronze bell with an electromagnetically driven clapper which alerted motorists to the approach of a train, it stood at an SP grade crossing in nearby Anaheim until the early 1960s when it was donated to the museum Union Switch and Signal relay cabinet, ca. 1940 and used to house the electronics powering the exhibitsThe display has since been expanded to include modern grade crossing signals, a US&S semaphore which once was mounted on a signal bridge spanning the Pacific Electric Watts Line and a century-old US&S banjo signal, used for both grade crossing protection and train control and one of only three known to exist.
The others are on display at the Smithsonian Institution. The Emma Nevada, a 3 ft narrow gauge Baldwin Locomotive Works 2-6-0 "Mogul" steam locomotive built in 1881, was purchased by Disney animator Ward Kimball and his wife Betty for their backyard Grizzly Flats Railroad in 1938. Built for the short-line Nevada Central Railway connecting Battle Mountain with Austin, the beautifully restored locomotive features Kimball's own artwork on the cab and headlight and was fired up in 1942. Boiler problems permanently sidelined the Emma Nevada in 1951. Kimball donated the locomotive to the museum and it can be seen today in the museum's Grizzly Flats car barn; the love of trains that Kimball shared with Walt Disney and fellow animator Ollie Johnston is credited with the idea of building a railroad in Disneyland in Anaheim, California. At Disneyland, a restored 1902 Baldwin 3 ft narrow gauge locomotive has been named after Kimball; the Ward Kimball, which entered service on June 26, 2005, is the first locomotive added to the Disneyland Railroad since 1959.
The Chloe, a 3 ft narrow gauge Baldwin Locomotive Works 0-4-2T steam locomotive built in 1883, was previously owned by Kimball and is displayed next to the Emma Nevada. Both are not operational. On July 28, 2017, the Chloe and its train car made an appearance at the media preview for the reopening of the Disneyland Railroad, they were pulled along its new route by the Justi Creek Railway's Marie E. locomotive driven by John Lasseter. The SCRM plans to restore the Chloe to operating condition; the Hillcrest Shops in Reedley, was selected as the location for the locomotive's restoration. The museum's newest locomotive, Santa Fe 108, is a 1967 EMD SDFP45 diesel locomotive. Featuring a 3600-horsepower, 20-cylinder prime mover and six traction motors, the FP45 was intended for fast passenger service and is geared to run in excess of 90 miles per hour. ATSF 98 is notable as being the last passenger locomotive purchased by the Atchison
Atchison, Topeka and Santa Fe Railway
The Atchison and Santa Fe Railway referred to as the Santa Fe or AT&SF, was one of the larger railroads in the United States. Chartered in February 1859, the railroad reached the Kansas-Colorado border in 1873 and Pueblo, Colorado, in 1876. To create a demand for its services, the railroad set up real estate offices and sold farm land from the land grants that it was awarded by Congress. Despite the name, its main line never served New Mexico, as the terrain was too difficult; the Santa Fe was a pioneer in intermodal freight transport, an enterprise that included a tugboat fleet and an airline. Its bus line extended passenger transportation to areas not accessible by rail, ferryboats on the San Francisco Bay allowed travelers to complete their westward journeys to the Pacific Ocean; the AT&SF was the subject of a popular song, Harry Warren and Johnny Mercer's "On the Atchison and the Santa Fe", written for the film, The Harvey Girls. The railroad ceased operations on December 31, 1996, when it merged with the Burlington Northern Railroad to form the Burlington Northern and Santa Fe Railway.
The Atchison, Topeka & Santa Fe Railway was chartered on February 11, 1859, to join Atchison and Topeka, with Santa Fe, New Mexico. In its early years, the railroad opened Kansas to settlement. Much of its revenue came from wheat grown there and from cattle driven north from Texas to Wichita and Dodge City by September 1872. Rather than turn its survey southward at Dodge City, AT&SF headed southwest over Raton Pass because of coal deposits near Trinidad and Raton, New Mexico; the Denver & Rio Grande Railroad was aiming at Raton Pass, but AT&SF crews arose early one morning in 1878 and were hard at work with picks and shovels when the D&RGW crews showed up for breakfast. At the same time the two railroads had a series of skirmishes over occupancy of the Royal Gorge west of Cañon City, Colorado. Federal intervention prompted an out-of-court settlement on February 2, 1880, in the form of the so-called "Treaty of Boston", wherein D&RG was allowed to complete its line and lease it for use by Santa Fe.
D&RG paid an estimated $1.4 million to Santa Fe for its work within the Gorge and agreed not to extend its line to Santa Fe, while Santa Fe agreed to forego its planned routes to Denver and Leadville. Building across Kansas and eastern Colorado was simple, with few natural obstacles, but the railroad found it economically impossible because of the sparse population, it set up real estate offices in the area and promoted settlement across Kansas on the land, granted to it by Congress in 1863. It offered discounted fares to anyone. AT&SF reached Albuquerque in 1880. In March 1881 AT&SF connected with the Southern Pacific at Deming, New Mexico, forming the second transcontinental rail route; the railroad built southwest from Benson, Arizona, to Nogales on the Mexican border where it connected with the Sonora Railway, which the AT&SF had built north from the Mexican port of Guaymas. AT&SF purchased the Southern California Railway on Jan. 17, 1906. The Atlantic & Pacific Railroad was chartered in 1866 to build west from Springfield, along the 35th parallel of latitude to a junction with SP at the Colorado River.
The infant A&P had no rail connections. The line, to become the St. Louis–San Francisco Railway would not reach Springfield for another four years, SP did not build east from Mojave to the Colorado River until 1883. A&P started construction in 1868, built southwest into what would become Oklahoma, promptly entered receivership. In 1879 A&P struck a deal with the Santa Frisco railroads to construct a rail line for each; the railroads would jointly own the A&P railroad west of Albuquerque. In 1883 A&P reached Needles, where it connected with an SP line. A&P built a line between Tulsa, Oklahoma and St. Louis, Missouri for the Frisco, but the Tulsa-Albuquerque portion remained unbuilt; the Santa Fe began to expand: a line from Barstow, California, to San Diego in 1885 and to Los Angeles in 1887. By January 1890, the entire system consisted of some 7,500 miles of track; the Panic of 1893 had the same effect on the AT&SF. In 1895 AT&SF sold the Frisco and the Colorado Midland and wrote off the losses, but it still retained control of the A&P.
The Santa Fe Railway still wanted to reach California on its own rails, the state of California eagerly courted the railroad to break SP's monopoly. In 1897 the railroad traded the Sonora Railway of Mexico to SP for their line between Needles and Barstow, giving AT&SF its own line from Chicago to the Pac
The Pennsylvania Railroad was an American Class I railroad, established in 1846 and was headquartered in Philadelphia, Pennsylvania. It was so named; the PRR was the largest railroad by traffic and revenue in the U. S. for the first half of the 20th century. Over the years, it acquired, merged with or owned part of at least 800 other rail lines and companies. At the end of 1925, it operated 10,515 miles of rail line, its only formidable rival was the New York Central, which carried around three-quarters of PRR's ton-miles. By 1882 it had become the largest railroad, the largest transportation enterprise, the largest corporation in the world. With 30,000 miles of track, it had longer mileage than any other country in the world, except Britain and France, its budget was second only to the U. S. government. The corporation still holds the record for the longest continuous dividend history: it paid out annual dividends to shareholders for more than 100 consecutive years. In 1968, PRR merged with rival NYC to form the Penn Central Transportation Company, which filed for bankruptcy within two years.
The viable parts were transferred in 1976 to Conrail, itself broken up in 1999, with 58 percent of the system going to the Norfolk Southern Railway, including nearly all of the former PRR. Amtrak received the electrified segment of the Main Line east of Harrisburg. With the opening of the Erie Canal and the beginnings of the Chesapeake and Ohio Canal, Philadelphia business interests became concerned that the port of Philadelphia would lose traffic; the state legislature was pressed to build a canal across Pennsylvania and thus the Main Line of Public Works was commissioned in 1826. It soon became evident that a single canal would not be practical and a series of railroads, inclined planes, canals was proposed; the route consisted of the Philadelphia and Columbia Railroad, canals up the Susquehanna and Juniata rivers, an inclined plane railroad and tunnel across the Allegheny Mountains, canals down the Conemaugh and Allegheny rivers to Pittsburgh on the Ohio River. Because freight and passengers had to change cars several times along the route and canals froze in winter, it soon became apparent that the system was cumbersome and a better way was needed.
The Commonwealth of Pennsylvania granted a charter to the Pennsylvania Railroad in 1846 to build a private rail line that would connect Harrisburg to Pittsburgh. The Directors chose John Edgar Thomson, an engineer from the Georgia Railroad, to survey and construct the line, he chose a route that followed the west bank of the Susquehanna River northward to the confluence with the Juniata River, following its banks until the foothills of the Allegheny Mountains were reached at a point that would become Altoona, Pennsylvania. To traverse the mountains, the line climbed a moderate grade for 10 miles until it reached a split of two mountain ravines which were cleverly crossed by building a fill and having the tracks ascend a 220-degree curve known as Horseshoe Curve that limited the grade to less than 2 percent; the crest of the mountain was penetrated by the 3,612-foot Gallitzin Tunnels and descended by a more moderate grade to Johnstown. At the end of its first year of operation, it paid a dividend, continued the dividend without interruption until 1946.
The western end of the line was built from Pittsburgh east along the banks of the Allegheny and Conemaugh rivers to Johnstown. PRR was granted trackage rights over the Philadelphia and Columbia and gained control of the three short lines connecting Lancaster and Harrisburg, instituting an all-rail link between Philadelphia and Pittsburgh by 1854. In 1857, the PRR purchased the Main Line of Public Works from the state of Pennsylvania, abandoned most of its canals and inclined planes; the line was double track from its inception, by the end of the century a third and fourth track were added. Over the next 50 years, PRR expanded by gaining control of other railroads by stock purchases and 999-year leases. Thomson was the entrepreneur who led the PRR from 1852 until his death in 1874, making it the largest business enterprise in the world and a world-class model for technological and managerial innovation, he served as PRR's first Chief Engineer and third President. Thomson's sober, technical and non-ideological personality had an important influence on the Pennsylvania Railroad, which in the mid-19th century was on the technical cutting edge of rail development, while nonetheless reflecting Thomson's personality in its conservatism and its steady growth while avoiding financial risks.
His Pennsylvania Railroad was in his day the largest railroad in the world, with 6,000 miles of track, was famous for steady financial dividends, high quality construction improving equipment, technological advances, innovation in management techniques for a large complex organization. In 1861 the PRR gained control of the Northern Central Railway, giving it access to Baltimore, Maryland, as well as points along the Susquehanna River via connections at Columbia, Pennsylvania or Harrisburg. On December 1, 1871, the PRR leased the United New Jersey Railroad and Canal Company, which included the original Camden and Amboy Railroad from Camden, New Jersey to South Amboy, New Jersey, as well as a newer line from Philadelphia to Jersey City, New Je