Sunday, 25 September 2016

German Forgings...

Great News...! At long last the tender wheel tyre forgings have arrived at Carnforth. After what seemed like endless delays the good news was phoned through from Rileys to Colin Vaughan on the afternoon of Friday 23rd September. Rileys will uplift them on Monday 26th September and hope to complete all fitting and machining by 7th October (estimated). The SRC will arrange transportation to collect the wheels and get them back to Aviemore as quickly and safely as possible. By that time the tender will be on the jacks in the Carriage Shed waiting to get lowered onto its wheels (hurrah...!!).

Meanwhile there is still work going on at Aviemore Shed. One unpleasant job has been to get at the injector shut-off valves inside the tender tank. The tank has a well at its front and deep in that well are set two shut-off valves operated from a pair of short levers on the tender front. The purpose of the valves is to allow the water supply from the tender to the loco to be isolated so that, for example, the tender can be uncoupled from the loco without having to drain the tank down. When 828 was last in operation it was noted that neither shut-off valve was functioning correctly. The valves can only be accessed by physically entering the tank and crawling forward through the tank internal framing to get to the well. After ventilating the tank thoroughly for a long period we made a controlled entry and confirmed that the valve operating rods were intact and functioning. Close examination showed that the valves weren't travelling fully and that some resetting was necessary. The work was carried out successfully by Tommy MacDonald and we are now able to rely on them once again.

The decision to reconnect the Westinghouse Brake Pump and operate it for demonstration purposes meant that we had to be confident that isolating cock on the boiler backhead (faceplate) was in good order. It has been fully stripped down and refurbished and should now provide a reliable means of on / off control for the Pump. By the way, if anyone has a Westinghouse Pump Governor in their attic it would be good to hear if you are willing to donate it for use on CR 828...! The Governor presently fitted to 828 has no internals. It will allow the Pump to be operated but only under manual control and without being connected to an air receiver. 

Our colleagues in the C&W Dept handed over a pair of wooden packing plates for the front buffers and these have been fitted. Because of material restrictions the new ones had to be made in two halves and glued together. They will do the job although they are a little undersized. However, one of our regular Volunteers, Aidan Bell, has very kindly offered to provide us with two fully-sized offcuts of oak that can be used to make another pair of spacers. These are due to be collected on 26th September from Wester Ross and will be machined to fit in the next few days.

The wooden packing plates provided by the C&W Dept. Note that John Greig has commenced repairs to the buffer beam paintwork.. Note also the absence of any inset access hatch on the fall plate (see bottom picture of CR 827..)

Inside the tender tank, Tommy MacDonald checking out the RH injector shut-off valve. The valve is normally protected by the dome-shaped strainer that Tommy has removed and placed on top of the operating rod. It's an awkward place to get to and one place where size really matters...

Close-up of the shut-off valve in the open position. The operating rod lifts and lowers the valve to open or close the flowpath. Interesting to see how much scale has deposited in the well since the tank was recoated at the last heavy overhaul completed in 2010.

Interesting picture borrowed from the Dunbar Collection showing the cab layout of CR 827 while the loco still carried its original boiler. There are quite a few differences from the LMS-pattern boiler fitted to 828. A couple of obvious ones being that the injectors were originally placed closer to the boiler centreline than they now are. In the next picture below of 828 you can see that the Westinghouse steam cock is now positioned inboard of the RH injector whereas 827 has the reverse arrangement. Note also that the cylinder drain cock operating lever was originally placed on the RH side of the cab in the vertical plane whereas on 828 it's on the LH side operated by a horizontal lever

The Westinghouse isolating cock undergoing refurbishment. The valve plug (a tapered cock) is being lapped into its seat using grinding paste to ensure a good metal to metal seal. To the right is the RH Injector with the slacker hose connection at the top. To the left is the RH gauge Glass..

A magnificent picture of CR 827 borrowed from the A.E. Glen collection. This picture dates from 1918. There are some interesting differences between 827 then and 828 now. Note that the fall plate (piano lid) above the front buffer beam has an inset hinged cover to give access to the steamchest lubricator - now long gone from 828 but something that we plan to reinstate if we can acquire or remanufacture the correct lubricator..

Saturday, 17 September 2016

Not Long Now....?

The tale of the tender tyre forgings continues. The most recent update came from a representative of the German tyre manufacturer who called in at WCRC HQ at Carnforth to apologise for delays in delivering the order that contains 828's tyres. Transport difficulties had arisen but all will soon be well was his message. Meantime the guys at Riley's are on standby to commence work as soon as the forgings are delivered....

At Aviemore work has carried on with a few jobs on the loco. John Greig has made up and fitted a set of new trimmings for the oil boxes on the motion and the loco is happily siphoning oil and dripping it into the pit. John has also started making repairs to some of the paintwork that was unavoidably damaged during the recent heavy work. Colin Vaughan and Chris Boyd are progressing the deep cleaning and polishing that will restore the museum finish that is an essential part of CR 828. 

Alan French has completed the manufacture of the new spindle for the boiler blowdown valve and returned it to the Shed so highly polished that it looks like a miniature FA Cup. Incidentally, Dr HJC Cornwell informed me that the purpose of the valve was not originally for blowing down the boiler but for desanding the rails after the driver had used the sanding gear. This became necessary when the LMS started to make widespread use of track circuits for improved train protection. The presence of sand on the railhead interferes with electrical continuity and desanding or rail washing was required to reduce the frequency of track circuit failures.

Because the blowdown valve wasn't fitted when we carried out the recent hydraulic test we're taking the opportunity to get it tested in isolation at the same pressure as the boiler (270 psi). Ken Donaldson has kindly offered to help with this.

Another valve that's getting attention just now is the Carriage Warming Valve (steam heating pressure control valve). The C&W Department had some reservations about the amount of water that seemed to flood into their pipework when 828 was last in operation. Having fully stripped the valve it's very clear that it could never have operated correctly. The operating principle is quite simple - steam at boiler pressure enters the valve and passes through a throttle valve that should drop the pressure down to around 30psi for the carriage pipework. The pressure is regulated by varying the the force on a diaphragm which controls the opening of the throttle valve. As found, this was impossible for our valve to achieve due to the absence of a pair of essential springs. Rectification work is in progress.

The CR828 Trust has agreed to a couple of small upgrades to their locomotive :

1. Conversion of the existing boiler pressure gauge to replicate the appearance of the original gauge. Not in itself a huge change but one that all are agreed will produce a very pleasing effect. Ken Donaldson has again very kindly offered to get this done over the winter. 

2. Reinstatement of the Westinghouse Pump for demonstration purposes. In addition to their beautiful deep toned whistle note, one of the sounds that characterised CR passenger locomotives was the panting noise of the Westinghouse brake pump (or compressor). The Caley used the Westinghouse system of compressed air braking rather than vacuum for their passenger stock and we would like to be able to let people see and hear 828's pump in operation. We know that it works as Brian Thomson had it at Bo'ness a few years ago for servicing and testing. Brian has offered to make up and fit the missing steam piping between the cab and the pump inlet. Initially we will simply discharge the air to atmosphere but at a later date it would be good to fit an air receiver and give the pump some work to do.

Boiler blowdown valve on the bench after returning from overhaul and polishing by Alan French

Draining down the boiler to make a trial fit of the blowdown valve. The primitive drainpipe is an attempt to keep the water away from the trailing axleboxes that lie under the cab floor..

The blowdown valve temporarily fitted without tightening the nuts fully. It's a close fit beside the RH Injector water cock - but there is enough room. The outlet pipe (not yet manufactured) will lead the water under the loco or into the ashpan

Several shades of blue...

Looking a bit smarter with the boiler handrail polished and varnished and the smokebox star polished too..

Shed Foreman Colin Vaughan hard at work (as a Volunteer) polishing the whistle and safety valves.

The Westinghouse Pump polished up by Colin Vaughan. The upper cylinder is the steam side with the inlet piping coming through from the cab. The lower cylinder is the air compressor. We look forward to hearing the "pant-pant" of the pump working again...

With the safety valves and whistle sparkling in the sun, Chris Boyd carries on restoring the lustre to the tender paintwork..

Taken from a Neilson Reid drawing  this is what 828's boiler pressure gauge will look like after Ken Donaldson modifies the existing gauge. The dial will be white. Ken tells me that a lot of people ask for the dial to be "aged" and produced in a shade of yellow - but it should in fact be white - a point also agreed by Dr HJC Cornwell.

Saturday, 3 September 2016

More Steam....

Another satisfying week with CR 828 - we completed several small jobs and then on Thursday 1st September raised steam once more to do some test running. The purpose of the testing was to ensure that the lubrication to the cylinders and steam chest is functioning. It also let us check out the operation of the brake ejector and the steam brake at a higher pressure than the previous operational tests the week before. As  expected we found a few minor issues, e.g. the small ejector valve appears to be stuck on its seat; the RH valve rod gland is blowing badly; the brakes are probably adjusted a bit too tightly but in general everything seems to be doing what it should..

Our main  concern now is the delivery of the tender tyre forgings to Ian Riley - the most recent date he gave us is Monday 5th September - let's hope this happens and we get the wheels back as quickly as possible. The weather in October can still be quite pleasant for operating a pre-grouping tender loco...

Steam locomotives use a lot of securing devices to stop bits falling off. These come in a variety of types. The most common are split pins (taper and parallel) and split cotters. In this picture we're looking up at the small end of the left hand connecting rod. The tapered wedge that closes up the small end bearing is secured by two split cotters. The pin that locates the strap that encircles the small end  is held tightly by the large nut which in turn is secured by another split cotter...

The four eccentric rods are bolted to the eccentric straps via the palm plate studs and nuts. The nuts are secured by split cotters. In this picture we can see that several of the cotters remain to be fitted..

Now in this picture we see that all the cotters have been fitted but those for the RH eccentric rods have not yet been opened out as we have still to complete the final valve setting checks on the RH valve (the picture is taken looking towards the rear of the loco)

This is the LH boiler feed injector. It transfers cold feed water from the tender tank to the boiler. It's a Gresham & Craven No.9 Injector. The Caley bought in a lot of proprietary parts from external suppliers and they normally bought their injectors from Gresham & Craven (still in business today). We needed to remove the two copper pipes at the bottom of the picture to repair some leaks and we also had a leak from the non-return valve that stops the boiler contents from leaking backwards through the injector..

Amy-Jane Budge inspecting the injector non-return valve seat after we removed the injector top fitting to get at the non-return valve.

The view into the top of the injector. Water being delivered into the boiler flows upwards through the non-return valve (not shown) and enters the boiler via an internal connection cast into the injector body. These injectors are known as "lifting" or "non-flooding" type as the injector body is set at a higher level than the maximum water level in the tender tank. They can be quite tricky in operation for firemen who are inexperienced with them...

Raising steam once again on September 1st. Old Faithful, the JCB doing its coal bunker act once again..

While waiting for steam Amy-Jane took the opportunity to wash down the boiler and prove that the Caledonian blue paint is still there..

Starting to look quite good again....!!

Back in the Shed and looking very smart indeed...

Gleaming under the Shed lights. Eagle-eyed viewers will have spotted that the boiler pressure gauge is showing 75 psi...!