My Merchant Navy - 'Royal Mail'
Words by Keith.
This 5 inch gauge Re-built Bulleid Pacific 35003, 'Royal Mail' was built by John Coleman, then in the Bristol Society, around 1990; using works drawings prepared by Bernard North.
The locomotive was exhibited at the 1992 Model Engineering Exhibition at Alexandra Palace, and was awarded a Bronze Medal.
The engine saw relatively little use since John Coleman who is a most prolific builder, went on to produce a magnificent 5 inch gauge King Arthur Class, other Southern Engines and a 7¼ inch GWR tank.
In turn, all these locos were sold to make room for the next.
How I came to own 'Royal Mail' was pure serendipity.
I'd built a 5 inch GWR 0-6-0 pannier, and was some way on with a 5 inch GWR Manor.
Progress was a bit slow and I had this wish to own a tender loco.
I found a Duchess for sale in the Midlands and mentioned this to a friend Don Cordall from the Bristol club.
He said he thought John was thinking of selling his Merchant Navy.
Don assured John that I'd be able to fix any problems myself, so after I'd spoken with John and he'd agreed to fit an ejector as required by the Cheltenham club, the engine became mine.
John fitted the ejector, saw it through a boiler test, the certificate having expired some years before, and duly delivered it to me in May 2000.
I couldn't wait to drive it and was soon up at the club and on the raised track.
Although the engine came with a current Southern Federation boiler certificate issued at Bristol, I thought I'd like one from my club in Cheltenham.
That was the first time I'd had it in steam and although it passed the boiler test, the first trial was disappointing since I couldn't get either of the two injectors to work due to problems with the clack and steam valves.
The axle pump in the tender wouldn't pump so I had to try to keep the boiler topped up using the hand pump.
Not a very auspicious start.
I bought a rise and fall trolley to support the engine and enable me to move it in the workshop, and to load it onto the trailer.
I modified the trolley so that it became a rolling road so the engine could be steamed at home, and set about putting right the problems.
The injector clack valves were cleaned and the SS balls replaced with nitrile ones, the steam valves were also cleaned and the seatings re-machined.
The boiler is fed by two injectors, an axle pump fitted to the tender and a hand pump also in the tender.
I found that at the beginning of each running season the axle pump refused to pump due to sticking of the clack balls.
I also modified these clacks to take nitrile balls and the problem went away.
When on the track for the second time it was much improved and then I realised that it was a very different beast to drive than the pannier.
Now the engine ran beautifully, the three cylinders making for a very smooth ride.
The firebox is huge and requires a thick fire and plenty of coal distributed to all corners, as well as covering the base to a considerable depth to keep up the boiler pressure of 80 psi.
On the Cheltenham and Bristol raised tracks, with their very gentle gradients, the engine can be notched up close to mid-gear.
Starting off with the safety valves lifting at 80psi, the regulator (push-pull in the dome) has to be opened very carefully to prevent wheel spin (just like the full size I'm told).
The beat of the exhaust when running is lovely and one can get carried away (metaphorically as well as literally) and forget to keep an eye on the fire.
That's when the pressure suddenly drops to 40 psi and one can panic.
Fortunately there is a very efficient blower and by carefully feeding the fire, the pressure returns to 80 pounds.
When this happens the three safety valves lift and since they are sited circumferentially in the boiler the effect is to emulate the Prince of Wales Feathers.
The controls on the back head consist of a steam fountain containing the whistle valve, pressure gauge, steam valve to the ejector, blower valve and two steam valves to the injectors.
The regulator is a pull-push lever type and although two water level gauges are fitted only one shows the boiler water level since John found that when running he saw different levels in the two glasses.
John also fitted a gauge to measure the steam pressure in the valve chest, (just for a bit of fun he said!!) and it is interesting to compare the very low indicated pressure when running light, say the driver and one or two passengers; and the much higher pressure with a full load as on a Public Running Day.
One realizes that with a locomotive of this complexity in time problems will occur.
These generally have been minor, but one more serious fault occurred when the die block in the link for the inner cylinder jammed.
Very carefully I managed to free it and smooth the sharp edges which had caused the stoppage without removing anything more serious than the running boards.
More recently, during a hydraulic pressure test, the main steam pipe stripped a thread in the smokebox and that had to be repaired.
It has been used fairly regularly for Club Public Running Days, and it is always a pleasure to show the engine publicly, as it attracts a lot of attention and envious looks from the young lads, and their dads.
On the C.M.E.S. 65th anniversary in 2003, the treasurer more or less comandeered the engine so as to impress the Mayor of Cheltenham and his wife.
The locomotive behaved perfectly.
It really is a lovely engine to drive, but because of its size I'm unable to run it on a friend's garden railway as it had a problem negotiating the curves, and derailed at every set of points.
Although I drive my pannier on this track, it would have been quite something to have gone round behind the Merchant Navy.