Technology of fireless steam locomotives
Steam storage technology uses the ability of water to store large amounts of energy under pressure.
The first fireless locomotive was built as early as 1882. Even then, the great advantages of fireless locomotives were recognized. Because they do not need a fireman, one-man operation has always been an important contribution to good economy. But also the simple, robust construction caused a lot of joy among the operators, as the fireless locomotives hardly caused any maintenance costs. Only the plain bearings of axles and rods, which were common in the past, required occasional workshop work. With today's roller bearings, modern fireless locomotives would be virtually maintenance-free.
By 1986, some 3,500 fireless locomotives had been built in Germany alone, some of which are in service today. With the replacement of the old steam locomotives, the ingeniously simple storage technology was unfortunately forgotten as well. But thanks to modern technology, it now once again offers an economical, environmentally friendly alternative for regional and works transport and can make a quick and substantial contribution to reducing CO2 pollution.
Most fireless locomotives are low-pressure fireless locomotives designed for relatively modest storage pressures of 8 to 20 bar. Since the storage pressure is constantly reduced during steam extraction, it is necessary to use oversized cylinders to prevent the tractive effort from decreasing likewise. Because saturated steam is fed to the steam engine from the pressure vessel, the specific steam consumption is relatively high, which reduces the radius of action. Low-pressure fireless locomotives were therefore used almost exclusively for shunting work in industrial plants with an already existing steam supply (chemical plants, refineries, paper mills, breweries, etc.), where they have proven their worth. Their operation is not only economical, but also extremely environmentally friendly. In most cases excess steam was used. Despite their relatively high specific steam consumption, they are particularly efficient for shunting, as they only consume steam when they exert traction. In contrast, diesel locomotives in shunting service have large idling losses (75 to 95% of the operating time is idling), which can reduce their efficiency to below 2%.
Fireless locomotives are emission-free, they emit pure water vapor. In addition, they are already explosion-proof due to their design and are therefore particularly suitable for chemical plants and refineries. Fireless locomotives do not require combustion air or oxygen for operation. This in contrast to diesel engines. Storage locomotives are therefore ideally suited for tunnel rescue trains.
Storage locomotives can also be called whispering locomotives, because they are noiseless when stationary and pleasantly quiet even under maximum effort. The remaining, rhythmic steam noise is significantly more pleasant than that of the noisy diesel locomotives.
In 1934, the first high-pressure fireless locomotive was built according to the principle of Prof. Gilli, for 120 bar! The high pressure technology has significant advantages as it allows to run with superheated steam and normal sized cylinders can be used. The lower specific steam consumption and the greater storage capacity thanks to the higher pressure enable the radius of action to be tripled compared to the low-pressure fireless locomotives.
Up to now, the applications of steam storage technology have been limited to fireless locomotives in works traffic. With modern high-pressure storage technology, however, the range of applications could be massively expanded. In rail transport, local trains are also feasible in addition to the tunnel rescue trains mentioned above. A large potential for reducing CO2 pollution could be realised by replacing construction and road vehicles in works transport and at airports.