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.

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