Back to Loco of the Month homepage
to Sidestreet Bannerworks


November 2009

Prescott Engineering's Robin

by Marc Horovitz

The model
Prescott Engineering was founded in 1994 by John Prescott. Robin is an attractive model of a typical British industrial locomotive. While it does not represent any particular prototype, it has many of the characteristics of the small engines that a variety of manufacturers supplied to commercial firms around the world.

A short but large-diameter boiler gives the engine a pleasing “chubby” look. The boiler has a single flue and is fired by butane. Gas is carried in a tank under the cab roof. To fill it, you slide back a hatch on the roof to reveal the filler valve – a nice touch. The gas-control lever protrudes from the front wall of the cab, just beneath the roof. While this sounds a little clunky and toylike, the valve is small, nicely made, and in keeping with the other fittings on the engine. It doesn't actually look out of place.

Boiler fittings include a safety valve under the lift-off brass steam dome, a throttle, a pressure gauge that you must read through a front cab window, and an ENOTS fitting for filling the boiler under pressure. A displacement lubricator sits next to the left side of the boiler. You need an allen wrench to open the drain plug.

Side tanks are dummies, as are the filler hatches atop them. Bodywork, according to the manufacturer's literature, is made primarily of nickel silver, not the customary brass or steel. Sheet-metal work is neat and cleanly done, with no rivet or other added detail. This is a plain, workmanlike locomotive. The chassis is unsprung and all axles are bushed in the frames.

The tiny cylinders have outside valves controlled by Hackworth valve gear. This is operated from the cab by a lever that locks into forward, neutral, or reverse positions. End beams are fitted with sprung (outside springs!) center buffers. Lamp irons adorn the smokebox and back sheet.

The run
Once the engine had been prepared for operation, I opened the gas valve and placed a match near the stack. The fire caught at once. For a single flue, gas-fired boiler, this one is remarkably quiet in service.

This is a very lively locomotive and is a challenge to run light. It does much better with a train – preferably a heavy one. I tried it running light first. It has an odd habit of speeding up and slowing down as the safety valve lifts. I found it difficult to reduce the fire to the point that the safety wouldn't lift.

After some exercise chasing the engine around my track, I tied on a short train. Even this helped considerably. The engine settled down quietly to its work with no more histrionics. It could easily have dealt with a longer, heavier train.

Robin has charming proportions and is a delight to see working in the garden. With the ENOTS fitting, it can be kept in steam indefinitely, shutting the gas down long enough to refill it. It's a fun engine to run.

Here's a movie of the engine in action. If it doesn't work, click here to go to YouTube.

Builder Prescott Engineering – John Prescott (UK)
Date built 1994
Gauge 0 gauge
Scale 1:24
Boiler Single flue
Fittings Safety valve, pressure gauge, throttle, ENOTS filler valve
Fuel Butane
Blow-off pressure 45 psi
Cylinders Two, double acting, D-valve
Reversing gear Hackworth
Lubricator Displacement
Weight 3 pounds, 12 ounces
Dimensions Length over end beams, 7-3/16"; width, 3-3/4"; height, 5-3/4"
This locomotive is virtual identical, one side to the other. Its short length, fat boiler, relatively large cab, and tiny wheels give it pleasing proportions for a small, industrial locomotive.
The cab interior, despite all the plumbing, is fairly simple. The pressure gauge faces out the front window. It could be turned around, if one wished. The circular thing above the throttle is the fuel tank. The lubricator is at the left, below the pressure gauge.
The reversing lever is to the right of the boiler. Notches in the quadrant ensure proper position for forward, neutral, and reverse.
A sliding roof vent conceals the gas filler valve. Gas is controlled by a neatly made, unobtrusive valve on the front cab wall (right).
Left: An ENOTS valve under the footplate allows boiler filling with pressure up. Above: The safety valve is concealed within an attractive brass dome.
Working Hackworth valve gear, unusual on a model, adds to this locomotive's charm. Because Hackworth valve gear could not be notched up and valve timing could be affected by uneven track, it was used primarily on industrial engines, where it performs well at slow speeds under less-than-optimal conditions.
There are no surprises underneath. The heavy axle bushes are evident. Aside from some spacers, there's virtually nothing between the frames.
Back to Loco of the Month home page

Back to Sidestreet Bannerworks home page

This page and its contents
Sidestreet Bannerworks, 2009