“Live steam” engines are the most realistic steam engine models. Live steam enthusiasts are skilled machinists who frequently construct their own detailed and intricate steam-powered trains. Live steam railroading is prominent enough to warrant its websites, magazines, and conventions, distinct from the larger world of model railroading.
In the 1950s, filmmaker Walt Disney operated one of the most famed live steam engines at his California home. Later, Disney constructed a narrow-gauge railway to transport visitors to his Disneyland theme park; as a significantly smaller but even so, fully functional train, which could be regarded as a very large steam engine model.
Continue reading to learn more about live steam models, a very beneficial modeling hobby.
What Are Live Steam Models?
A live steam device or machine is powered by steam. Still, the term is usually reserved for replicas, toys, scale models, or other items used for heritage, entertainment, museum, or recreational purposes, to differentiate them from similar devices fueled by internal combustion, electricity, or another more convenient method but designed to look like they are steam-powered.
Revenue-generating steam-powered machines like full-sized steamships, narrow gauge, mainline steam locomotives, and steam turbines used in the global electric power generation industry are not typically referred to as “live steam.”
Traction engines and steamrollers are popular, in 1:4 or 1:3 scale, and so are model stationary steam engines, varying from pocket-size to 1:2 scale.
Railways or Railroads
Large-scale, ridable live steam railroading on the backyard railroad is a common aspect of the live steam hobby, but building a locomotive from scratch takes time and can be expensive. Garden railways on smaller scales (which cannot pull “live” people or be ridden on) provide the rewards of real steam engines (in less space and at a lower cost) but do not offer the same experience as running one’s locomotive in larger scales and cruising on (or behind) it while doing so.
Walt Disney’s Carolwood Pacific Railroad was one of the most famous live steam railroads; it later influenced Walt Disney to enclose his planned Disneyland amusement park with an operating, narrow gauge railroad.
The live steam hobby is particularly popular in the United Kingdom, the United States, Australia, New Zealand, and Japan. There are many associations and clubs, in addition to thousands of personal backyard railroads, worldwide.
Train Mountain Railroad in Chiloquin, Oregon, has the world’s largest live steam layout, with more than 25 miles (40 km) of 7+12 in (190.5 mm) trackage. The Riverside Live Steamers and the Los Angeles Live Steamers Railroad Museum also operate unique layouts.
Scale
A live steam locomotive is frequently a precise, hand-crafted scale model. The number of scale inches per foot is commonly used to describe live steam railroad scales.
A 1:8 scale locomotive, for example, is frequently referred to as a 112″ scale locomotive. Popular modelling scales are Gauge 1 (1:32 scale), 3/4″ (1:16), 1/2″ (1:24 scale), 1″ (1:12), 2½” (~1:5), 1½” (1:8), and 3″ (1:4).
Track Gauge
The gap between the rails is called a track gauge. The track gauges available range from 2+12 in (64 mm) to 15 in (381 mm), with the most popular being 5 in (127 mm), 3+12 in (89 mm), 7+14 in (184 mm), 4+34 in (121 mm), and 7+12 in (190.5 mm). Gauges of 10 in (254 mm) and up are referred to as “Miniature Railways” (in the United States, these are referred to as “Grand Scale Railroads”) and are mostly used in commercial settings and amusement park rides.
Because you can build larger equipment in a narrow gauge railway configuration, the gauge often has nothing much to do with the scale of a locomotive. On a 7+12 in (190.5 mm) track gauge, for example, scales of 1.5, 2.5, 1.6, and 3 inches per foot (value corresponds to 1:8 to 1:4 scales) have been used.
O scale is the most commonly used gauge for a live steam locomotive. Manufacturing smaller-scale models remain difficult because physical laws do not scale: building a small-scale boiler that yields useful quantities of steam requires careful engineering.
Hornby Railways has manufactured commercial live steam-powered locos in OO scale using an electrically heated boiler installed in the tender, cylinders within the locomotive, and control supplied by electrical signals supplied through the track from a remote-controlled unit. They are less mechanically accurate than larger-scale models; the visible valve gear, like on the electric-motor-powered models, is a dummy, and steam admission to the cylinders is managed by a rotary-valve servo within the boiler casing, which is also a dummy. Nonetheless, the locomotive is powered by steam generated on board and is thus a real steam locomotive.
Even smaller functioning steam engines are technically possible. Hand-made examples as small as Z scale (1:220) have been produced, with a gauge of 6.5 mm (0.256 in). These are powered by a butane flame from a tender burner on the engine.
In the 1960s and 1970s, AA Sherwood, an engineering lecturer from Australia, produced some mini-scale model live steam engines. His smallest engines were the 1:240 scale, smaller than Z Scale’s 1:220. Sherwood worked on the smallest scale, 1:480, but it was not live steam.
Technology
Boiler designs range from externally fired potboilers to superheater boilers and sophisticated internally fired, multi-flue boilers, typically found only on more complex, larger models.
You can use a simple valve gear for basic locomotive models, with reversing (if any) executed by a valve or employing a “slip” eccentric. More intricate locomotive models can employ valve gear similar to actual steam engines, with mechanical reversing, most commonly the Walschaerts type.
Fuels
In live steam models, the following fuels are commonly used to boil water:
Hexamine Fuel Tablets – generate little heat but are inexpensive and safe. They are frequently used on “toy” live steam engines and locomotives, such as Mamod’s newer models.
Methylated spirit (ethanol/methanol mixture) – burns hotter than a solid fuel but, like any flammable liquid, must be handled with caution. This fuel was used in early Mamod models because it was inexpensive and easy to obtain.
Butane gas – safe and clean burning, but the burners are relatively expensive to design.
Electricity – supplied via track and used to heat the water using an immersion heater. Hornby introduced a line of 00 gauge models in 2003 that uses a 10 to 17 Volt power source, making this approach safer than prior, higher voltage versions.
Coal – is the most common fuel for full-sized steam locomotives and the favored fuel for ridable trains. You can also use I t in boilers with a scale of at least 16mm:1 foot.
Oil – is a common fuel for large, rideable trains as well.
Propane gas – a substitute for oil or coal in large-scale models. Propane has also been successfully used as a fuel in 1:48 scale live steam locomotives, most notably those produced by Roland Neff.