Last Known Steaming

Anticipating an interesting day out, I visited the Langport steam rally on Sunday July 21st 2013. As well as four Sentinel steam waggons, there was a grand array of traction engines, tractors, old vehicles and sales stands plus lots more.

Quite unexpectedly, I spotted a book I'd not come across before called 'Steam Engines at Bressingham' by Alan Bloom which, after a little, gentle haggling, I bought.

ISBN 0 571 09462 7, 1970, Faber & Faber

In an article I posted mid 2011, I made reference to the fact that Sentinel 7109 had been transferred to Bressingham in 1968. Indeed, in the 1970 booklet 'The Bressingham Book - Gardens, Steam Railways and Engines', Sentinel 7109 is shown in the Bressingham museum interior (far left of picture in green).

7109 at Bressingham (SBN 8530 206 4)

So in 1970, it can be assumed that Sentinel 7109 was still at Bressingham.

What really caught my eye was one particular paragraph talking about the various Bressingham steam engines...

"This too was a Gas Works shunter, but of a very different type, for it was a Sentinel. Once again the good offices of J. B. Latham of the Industrial Locomotive Society had come into play. The South Eastern Gas Board were dispensing with steam at their Croydon works, and had presented it, together with a good supply of spares, for preservation. This very unconventional looking locomotive, with its vertical boiler almost filling the cab, had two enclosed engines and was chain driven. It had in fact more the outward appearance of a diesel than of a steamer, but because it was different from anything else I was glad to see it come to make the collection more comprehensive. Roger [Garnham] was something of an expert with Sentinels, having driven one often enough for a previous employer, and he was anxious to see it in steam. Steam was raised, but this preliminary test was not carried far. The steam brake failed to work and other minor faults consequent on its being discarded for some months would have to be put right before another attempt was made."

I don't believe another attempt was ever made so it seems that just prior to the 1970 publication date was the last time Sentinel 7109 had its fire lit.

I had previously not known of this and had assumed incorrectly that the last steaming date was around 1960 when it was taken out of service.

When we examined the steam brake cylinder 40 or so years later in 2011, it was in a really poor state. Even with the lapsed time, it's pretty obvious why it could not be made to work at Bressingham.

Oil Out, Oil In, Oil Out

With the July 2013 heatwave has come the opportunity to do an oil change and refill; the hot weather makes the oil less viscous and hence easier to drain.

Oil Sump Drain Valve

Draining the engines was fairly easy although the drain valves need to be removed completely to get a reasonable flow rate. (The valves are mainly used to drain off condensate that has settled below the oil).

I then began to fill the other oil chambers including the one below which lubricates the shaft used to move the camshafts axially.

Oil Filler (and Emptyer!)

It was easy to get the oil in through the filler hole (with the hex screw-head showing) using a small funnel. Unfortunately, I soon found that there were leaks around where the filler hole support meets the left and right castings.

I loosened the filler hole support and cleaned all the mating surfaces which should provide the seal. I then slapped (technical term!) a load of Heldite on the surfaces and screwed it together again - tightly.

After a while, despite considerable care, I refilled the oil and ... you guessed it, it was no improvement from before and now there is the Heldite in the gap also around where the oil is leaking.

I'm forming the opinion that this was perhaps not one of Sentinel's best designs unless there was originally a gasket present.

Looks like I have an extra task ahead to make an almost cylindrical gasket to wrap around the joint; otherwise, oil consumption will not be a strong point!

Hidden Secret

Sometimes the simplest looking items turn out to be more complicated than expected. The off-side water feed valve is one of these.

WS BFP Water Feed Valve

And the same but closer (restored)

It's a 'Plug' valve with a tapered plug and rectangular slot. The plug is held down into the valve body by a screw-down gland plate. These are fairly simple ideas; however, the valve body and its spindle have a hidden secret.

The 'Plug' (Spindle)

Valve body

On the surface, it's easy to see the rectangular slot in the plug which either allows water through or blocks the flow depending on which way it is set.

There is a slot around the top of the plug taper with a pair of holes diametrically opposite each other. So what are they for?

On the top of the spindle is also a hex headed screw. So what's that for?

Hex head screw

Initially, the hex head was well jammed-in with old paint and immovable. With a split-pin hole across the hex head, it looked as if it might have had a purpose at one time. I dug the paint out and managed to free the screw and its purpose began to become clear.

On removing the hex head screw, I could see another screw inside the spindle hole so I removed that too.

Hex head and internal screws

At the bottom of the hole in the spindle is a chamber with the pair of holes leading off to the slot around the top of the plug.

The internal screw is more subtle than I'd initially imagined.

Internal 'screw'

In fact, it is hollow and contains a ball bearing retained by a loop of wire. With a pair of slots at the lower end, the ball acts as a non-return valve.

With the screw in place at the bottom of the spindle hole, grease is loaded into the hole above (best done with a grease gun). The hex head screw is then screwed in to push the grease through the valve and out through the holes to the slot around the top of the plug.

The valve body design works with the plug to distribute grease to all the places it is needed.

Inside the valve body

Looking down into the body, there is a cut-out in the wall which coincides with the slot around the top of the plug. There is also another cut-out at the bottom of the body (the plug-hole?). There are also identical cut-outs opposite the ones visible in the photo. The cut-outs also coincide with four slots down the plug surface.

One of the four plug slots - Note the dark patches at each end of the slot
which match the top and bottom body cut-outs

The grease can thus be forced down into the slot around the plug, through the upper body cut-out, down the slots and finally into the lower cut-outs and the bottom of the valve body. The whole valve can thus be greased in situ whilst doing its job immersed in water. Clever!

A few notes:

Grease can be forced in with the valve spindle in any position. The cut-outs will prevent grease ending up in the water space.

The valve is open when the top looks like this:

Valve Open

The valve is closed when the top looks like this:

Valve Closed

The slot through the plug is in line with the 'pips' on top of the spindle.

Slot lines up with the 'pips'

Not a lot of people know all that!

Recreating an old Photo

I've had this photo for some time and have used it to examine small details of the cab and the Boiler Feed Pump peering from the cab side window.

1933 (Photo - Tony Thomas collection)

Here it is again but this time in June 2013. It was difficult to get the same angle but it's not far off (and I really should have hidden the display panel and put the covers on!).

2013

I've used this cropped-from-the-top photo before to show the pump itself.

1933 BFP Close-up

Send me a comment if you can identify the BFP type shown above. Out of curiosity I'd be interested to know the type (but am unlikely to try to find one - a task lodged firmly in the too difficult pile!).

Here's the new BFP in place. A Worthington Simpson type was specified for a later Sentinel double-engined loco so that's what it will have to be.

2013 BFP Close-up

Welcome WDP (& other) Readers!

Western Daily Press journalistic staff members Suzanne Savill and her photographer Clare Green paid me a visit on May 30th 2013 and we 'had a little chat' about Joyce and her foibles.

The WDP Article - Click to enlarge

The result is the wonderful article above on pages 8-9 of the WDP West Country Life section for Saturday June 8th. Suzanne must have been listening very carefully to my techy ramblings as she has caught it all in detail. Well done Suzanne!

There's one small error but it did make me laugh. I'll keep it to myself and use it as a talking point - see if you can figure it out!