Sunday, 22 May 2016

Tyred and Emotional

A week of good progress..! Colin Vaughan called in the Inspection company used by the SRC to carry out NDT (Non Destructive Testing) on 828's wheels and axles to ensure that they remain fit for further service. This is something that has to be done every ten years. The objective is to use a range of techniques to check for any cracking in axles and wheel spokes. Reassuringly the Inspector found that all axles and wheels on the loco and tender remain in excellent condition and the next inspection will be due in 2026...

We carried out an "in-house" hydraulic test on the boiler to check for any problems ahead of inviting the Boiler Inspector to witness a formal test. The test is carried out at the boiler working pressure (180psi) x 1.5 = 270psi. With the boiler pumped full of cold water at 270psi Colin carried out a thorough check in the firebox and the smokebox as well as externally and we were very pleased with the outcome. The Boiler Inspector has been booked to come in and witness a repeat test during week commencing 23rd May. Assuming that this is successful we can move forward to the next stage which is to prepare the boiler for an inspection in steam...!

During the week we removed all six of the tender wheel tyres. This work was largely carried out by Calum Titley and involved a lot of very careful and skilful use of oxy-acetylene burning gear. The tyres are shrunk onto the wheel centres and then locked in position using Gibson Rings. This gives a very secure attachment but is difficult to undo and it took some perseverance to work out the best method of removing the Gibson Rings. Once we had established a suitable method it was then reasonably straightforward to apply it to all six wheels. The wheel centres are old but in pretty good condition. We found evidence of an older method of tyre attachments that predates the Gibson Ring method - this relied on a shrink fit plus the fitting of rivets through tyre and wheel centre. In one case there are a couple of cracks on the surface of the wheel centre along the line of the redundant rivet hole. Ian Riley's firm, who will fit the new tyres, have confirmed that they can make the necessary repairs.

The valve eccentric straps have been reassembled and are ready to be transported with the eccentric sheaves to Northern Ireland for machining. This should happen in the next week or so.

Roddie McCrae has done great job in cleaning up all six of the tender axleboxes and making sure that the oiler pads are clean with fresh oil in the sumps.

The tender axleboxes after cleaning and filling with fresh oil. The oiler pads can be seen in position with the tails of the trimmings dipping into the oil sump. The Caley made their tender axleboxes a generous size...

Checking for cracks in wheel spokes...

Eddy Current crack testing the tender wheels..

Calum Titley making a start on removal of the first tender tyre..

Cutting through the tyre to expose the wheel centre...

First section of tyre removed....

First tyre successfully removed..

Getting more practised now.....tyre removed with only a single cut...

Master of the art of tyre removal....Calum shows how it's done..!

Our ever increasing pile of scrap tender tyres...

In Calum's absence, an amateur takes over - watched carefully by John Greig...!

Colin Vaughan making it look very easy to drive the Shed JCB..
The scrap pile is complete. The centre wheelset is parked out of the way while two diesels reflect on a scene they remember well from the 1960s..

Close up of a section of Gibson Ring showing how it fits into the annular groove in the wheel centre. The tyre has a similar annular groove into which the ring is fitted. Once the ring is in place a lip on the back of the tyre is swaged over the top of the ring to hold it in place.

The old way of securing tyres----a redundant rivet hole..

Cracking along the line of one of the redundant rivet holes. Riley's assure us that a repair is straightforward.

Eccentric straps assembled in preparation for transport to Northern Ireland

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