Steam engine speed in reverse
 

Hi all

Hope you don’t take offense, I’m not a train modeller, and only have a passing interest in trains, but I’m writing a story about Malaya 1941-42, and would like to ask some questions. The FMSR (Federated Malay States Railway) ran the railway in Malaya, on a metre gauge network, which was mainly single line working. So, at the end of a journey, there would have to be a turntable or a loop, to turn the engine around. But if not, then I guess an engine would have to reverse back.

So, question, can a steam engine reverse as fast as it can go forward, and I’m only expecting speeds of 30-40 mph as a max, quite possibly slower, and how do you switch the drive into reverse on a steam engine

Hi Fatboy

A steam engine goes into reverse by moving the 'reverser', which serves much the same function on a loco as a gearbox does on a road vehicle, from forwards into back gear. However there are no gears on a steam engine, and the change of direction is achieved simply by changing the way in which the valves admit steam to the cylinders – the pistons continue to act in exactly the same way regardless of the direction of travel.

On most tender engines the speed in reverse is limited to rather less than when in forward gear. This is partly because it can be seen as less safe to be propelling the heavy weight of the tender ahead of the engine. This might be particularly the case on lightly laid lines such as might have existed in Malaya in the 1940s. In addition the driver's outlook to the rear of the engine is often less clear than his view ahead, so more caution is required.

In the case of tank engines – locos with no tender – the speed in reverse can generally be the same as when going forwards, though drivers may have a rather restricted view and so may well wish to drive a bit more slowly.

On the Rhodesian Railways, the Garratt loco's could travel in both directions at the same speed. As the coal tender was slightly narrower than the cab, the crew could see better in reverse than the view forward, but it was rear for a loco on the main line to travel in reverse. Facing forward, there was the fire box, the boiler, then the front water tank. Facing the rear of the loco, there was only the coal tender. The cab was wider than all the rest of the loco, so that both crewmen could see well ahead of the train. As with all railway crews, the fireman was required to alert the driver of the signal ahead if the signal was on a carve and not visible to the driver. We all knew where the signals were, and if I was firing, the driver would look out of my window to check the signal was set to clear.

Ok thank you for this guys

Below is a link to my picture of the Umgeni Steam Railway loco named "Maureen" (number 1486) going in reverse. It's the only way to return to the starting point as there are no turntables on the line. After dropping the passengers, they couple the loco on the other end and return to the depot. You can look up http://www.umgenisteamrailway.com. Since the starting point is not at the depot, the first and last trips do not carry passengers. They do the downhill leg in reverse, I'm not sure if it is a coincidence or calculated.

The Watercress line in England also doesn't have turntables so each alternate trip the loco is in reverse.

Here is the link to the picture https://i73.servimg.com/u/f73/17/29/29/41/104_0710.jpg

Funnel forward up hill.
I have only swung the banjo on a soot belcher way back in the early 1990s.
But, I do remember one of the usual policies.
Where a steep grade exists on the route, the soot belcher should face funnel forward for the climb.
That ensures that the firebox crown sheet is covered by water.
When running tender forward on a climb, the fireman must maintain sufficient water in the sight glass to ensure covering the crown sheet.
As I discovered on my first run, working bunker forward for the first return to Lithgow climbing the hill to Marrangaroo tunnel, judging that level can be difficult for a novice.
I had to fire against the feed for the climb.
I lost sight of the water glass while inside the tunnel and the soot belcher primed (took water) due to that water level being very high.
The loco inspector was NOT amused when we arrived at Lithgow station.
So, we took the soot belcher into loco to swing it on the turntable to then onwards face funnel forward for that long climb.
Resulting that I didn't need so much water in the sight glass to ensure covering the crown sheet.
As to max speed when running tender forward, the NSWR working timetables listed that.
Such was also generally stipulated in the Instructions for drivers and firemen.
Generally when running tender forward, the max speed was restricted to 40 MPH.
Except when the tender was only a light three axle version in which the max speed was 30 or 35 MPH.
The CME could issue alternate instructions for special conditions to increase that max speed if necessary.
I recollect loco speed regarding direction of travel being mentioned in the forum previously, but forget just which posting that was.
Steve.

Again, thank you