How do funicular railways work? Funicular railways operate through a rack and pinion system, where a toothed flywheel on a locomotive or piece of rolling stock connects to a toothed rail, thus, pulling the train along the guide rails.
A funicular, or cog railway traces its routes to England in 1812, when the cog railway was invented by John Blenkinsop. During the pioneering days of the railway, Blenkinsop believed that locomotives would struggle to gain traction by adhesion alone. Therefore, in the early 19th century, he patented his form of the cog railway, in which a toothed rail was located outside the track gauge, and operated by a cog wheel on the locomotive, thus improving traction power.
Blenkinsop began producing locomotives with cog wheels for the newly constructed Middleton Railway, which was a privately owned railway built for the purpose of hauling coal for the local colliery. The locomotive was built with a cog wheel, which engaged a toothed rack, which included roughly two teeth per foot of track. The first cog locomotive, Salamanca, built by prominent engineer Matthew Murray, was the first commercially successful steam locomotive. With the advancement of the railway underway, locomotives operating under adhesion alone was becoming the standard, especially with the opening of the Stockton and Darlington and Liverpool and Manchester railways. This form of rack railway is considered rack and adhesion, as the locomotive provided power, however, the cog system provided the additional tractive effort. The rack system on the Middleton Railway became antiquated, and was removed in 1837, in favor of adhesion locomotives. Although the Middleton Railway lacked steep grades, the cog system was only utilized to assist in hauling the heavy coal chaldrons from the collieries.
In the modern era, rack railways are mainly utilized on steep mountain grades, as either a rack-only railway, where the wheels engage with the rack system in the railway’s entirety, or some railways only utilize the rack railway when tackling a steep gradient. Some railways, for example in the Swiss Alps, have sections of cog railway when the gradient begins to steepen, however, runs on solely adhesion on the remainder of the railway. The Mt. Washington Railway, America’s first cog railway built in 1868, utilizes the cog system in its entirety. Developed by Sylvester Marsh, the railway was designed to ensure that at least two teeth are engaged with the rack, to ensure maximum performance. According to Bruce D. Heald’s book “The Mount Washington Cog Railway”, Marsh describes his patented rack system:
The present invention related to that class of locomotives, which are used for ascending very steep grades, and has for its object, first, obtaining sufficient power to ascent a steep inclination with a light locomotive instead of a heavy and cumbersome one, such as have heretofore been necessarily used; second, preventing the possibility of the engine being thrown off or lifted and un-geared from the track by the interposition of any obstruction thereon, and the means employed for checking and stopping the progress of the train.
Heald, Bruce D.. The Mount Washington Cog Railway: Climbing the White Mountains of New Hampshire (Transportation) . Arcadia Publishing Inc.
In addition to Blenkinsop, various other forms of cog railways were devised throughout the years. Sylvester Marsh developed his cog railway in North America in 1868, when the Mt. Washington Railway began operating utilizing his patented cog system. Marsh’s system operates by the cog wheel engaging in the toothed rail in the center of the gauge, where the toothed rail is similar to the rungs of a ladder, in which the cog wheels engage one by one. To ensure that the pinioned cog wheel remains engaged with the rack, the rack is constructed so that two teeth are always engaged with the rack. The Mt. Washington Cog Railway is one of the most scenic rail journeys in North America, as it takes passengers to the summit of the mountain for a breathtaking view.
Marsh’s system was similar to Niklaus Riggenbach’s system, a French inventor who patented his own system, which took interest from the Swiss. However, Riggenbach’s system suffered from a more complex ladder type rack which was more expensive to build and maintain than Marsh’s. An improvement upon the Riggenbach system was devised by Carl Roman Abt, who created a less complicated rack system, and improved the transition from rack to adhesion railway. Many rack railways did away with the locomotive completely, as the railway was powered through the rack, which turned the cog wheel, thus, the stock had free rolling wheels. Many cog railways even lacked flanged wheels on their rolling stock, as the cog wheel would guide the train. An example of a railway that only has rack rail on steep inclines is Switzerland’s Glacier and Bernina Expresses,as they are not full cog railways, as the cog rack is only located in the steepest parts of the route. The railway utilizes a transition rail that the cog wheel is guided along until it reaches the rack. This makes for a smoother transition from purely adhesion to rack traction.
Perhaps the most complex part of the cog system are the switches or turnouts. Many cog railways would have turnouts on flat land when only adhesion is necessary. If a turnout is necessary with the rack rail present, it is easier to construct a turnout and bend the rail when the rack is above the running rails. The switches operate by using a series of bell cranks and push rods, which link the switches’ throw-rods to the moving sections of the rack. However, when the rack was located below the running rails, such as Marsh’s system on the Mount Washington Cog Railway, it was increasingly difficult. Therefore, initially Marsh constructed the railway without turnouts. However, in 2007, automatic hydraulic turnouts were installed, which acted as a transfer table of sorts.
Cog Railway Rolling Stock
Because of the steep grades of cog railways, those that utilize steam locomotives must adapt to the mountainous terrain. Components such as the boiler and cylinders must be adjusted, as the water in the boiler must cover various components, however, on an incline,a normal horizon boiler and cylinders would not be sufficient. Looking at a cog locomotive, one may notice the components of the locomotive such as the boiler and cab, are tilted towards the wheels. This allows for the locomotive to operate properly, as the boiler and other components of the steam locomotive must be level in order to operate correctly. When in operation, it is imperative that the water in the boiler covers the crown sheet and boiler tubes. If these components are not covered properly with water, the locomotive will fail. When in operation, these locomotives must always be on an incline, as even the maintenance facilities on many cog railways are on the side of a steep grade.
Interestingly, due to the boiler issues of steam locomotives, many cog railways were electrified as soon as the technology and infrastructure was viable. The most notable electrified cog railway is the Pilatus Railway, which runs through the Swiss Alps. The railway is a full rack railway, and utilizes an electrified tram as rolling stock. Some locomotives, for example, Switzerland’s Vitznau-Rigi Railway, owns locomotives with completely vertical boilers to negate these issues. Vertical boilers hinder the speed and efficiency of the locomotive, however, many mountain cog railways move at a slower pace. Because of the steep grades on the cog railways, many cog locomotives are equipped with powerful brakes, many even equipped with disc brakes for superior stopping power.
For more information about cog railways, Bruce D. Heald’s publication, “The Mount Washington Cog Railway: Climbing the White Mountains of New Hampshire”. (Link to Amazon)