Armstrong Exploratory
Steam Juggernaut:
Implacable, Efficient, Affordable!
The Armstrong Exploratory Steam Juggernaut has been especially developed for the use of expeditions working in the wild and dangerous areas of Earth, Mars, or Venus. A forced draught Scotch boiler working at 120 p.s.i provides steam to two 125 horsepower two-cylinder compound expansion engines, sufficient to drive the juggernaut at a rate of 10 miles per hour, and to traverse slopes of up to 10 per cent grade. Each engine drives a track system of the Smith-Petlolly pattern. An ingenious ventilation system draws any objectionable fumes from the crew compartment, while simultaneously providing clean air from without. Up to fourteen tons of fuel can be carried in bunkers on the lower deck, sufficient for up to two weeks of continuous travel. The boilers can work equally well upon wood, coal, straw, peat or other flammable materials, although the efficiency of the engine may decrease somewhat when burning marginal fuel.
The design of the Juggernaut is such that amphibious operations are possible, allowing the traversal of littoral and riverine terrain. The upper or 'return' section of the tracks is just above the waterline of the Juggernaut when fully loaded. It is not possible to employ the Maxim guns when floating. The bow winch may be employed to draw the Juggernaut along steep or otherwise impassable slopes and surfaces.
Maxim guns of .303" calibre are fitted on either side of the bow, with several thousands of cartridges at hand for continuous fire; they can be withdrawn by the crew for deployment on the provided tripods. Upon the bridge is a 1 pdr. machine cannon, sufficient to deter any native attack; racks for rifles, cutlasses, and other small arms are incorporated into the comfortable crew compartment. The hull is composed of armor steel two inches thick, with protected visor-ports for the Maxim guns; the visor-ports can be sealed when the guns are withdrawn, to prevent the ingress of water or other harmful fluids.
An engineer, wiper, and stoker tend to the machinery; a skilled tractor-driver guides the Juggernaut across the landscape; three gunners man the armament, and act as a landing-party; six passengers and a commander have their places. Cargo in the amount of four tons can be carried internally or externally.
A periscope is fitted for the use of the passengers in viewing the passing terrain; canvas awnings may be erected above the open bridge and boiler areas, to shield the crew from the sun's rays or inclement weather. Hatches to either side allow the passengers and crew to embark and disembark with rapidity and ease.
| Width: over hull 12 feet, over tracks 18 feet | Weight loaded: 50 tons |
| Length: over hull 26 feet, overall 30 feet | Weight empty: 32 tons |
| Height: to roof 13 feet, to top of stack 19 feet | Cost complete £7000 FOB Sheffield |
The interior spaces of the Juggernaut are:
-- the bridge, an awning-covered position up front. The main gun is also fired from here. Searchlight, signal flags, racks for rifles and cutlasses, steering wheel and engine controls. A ladder leads down to ...
-- the passenger quarters, below the bridge area. Puckered leather benches, storage cabinets, framed prints, water taps, gun visors, lots of brass and leather. A periscope extends upwards from here. Two doors lead aft to ...
-- the engine room, with the engines on either side of the boiler, and the bunkers aft. The top of the engine space is open to the sky, with gratings and awnings to keep the weather and sun out. Large doors on either side allow the crew to enter and exit the Juggernaut, and for the loading of fuel.
For each ton of coal burned, four tons of water are evaporated in a period steam engine. Steam railway locomotives normally just exhaust this as steam, and get more water from trackside water tanks. Condensers will prevent this water from being lost, but these in turn require cooling; steamships do this with conveniently available salt water; but some railway locomotives used in dry areas, and aerial flyers on arid Mars, must use condensers, essentially giant radiators. The six tons of 'boiler and engine' for the Juggernaut probably includes a ton of water in the boiler itself, a ton in a storage tank, and a ton involved in the condensing equipment.
The boiler can burn various materials; changing the firebox to adjust between oil/coal/wood/plant waste takes a few hours, plus letting the boiler cool down far enough so that you can work in it, and heating it up again afterwards ... essentially a full day's work for the engine crew.
| Fuel Oil: | 1.33 (consumption x 0.75) |
| Coal: | 1 |
| Hard Wood: | 0.8 (consumption x1.25) |
| Soft Wood: | 0.5 (consumption x2) |
| (for green or rotten wood, fuel value halved, consumption doubled) | |
| Mummies, oil-rich plants (such as flax): | 0.5 (consumption x2) |
| Dry straw, dung, corn cobs, peat, etc.: | 0.4 (consumption x2.5) |