LSWR T3 563

Essentially to enable a good display perhaps you don't need to keep the whole box essentially cutting it in half so it's easy to see the inside otherwise people have to peer through the fire hole to see all the repairs on the 'normal' side, just a thought.


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I'm confused by this also, but I'm not a boilersmith, my boiler experience went as far as restaying and trueing up mounting faces, I would have thought that the idea of a patch was to re inforce a failed section of plate by screwing and riveting a plate over to seal a crack as a short term measure until the engine can enter the boiler shop I would have thought that cutting out of plate then using a patch repair would only be a time limited fix, 563 I would think was not expected to have any major work done after the war, it would have been earmarked for scrap once no longer of use, it was pure luck she was chosen, i'm guessing the others inspected were in a far worse condition .

 

Techniques Julian, techniques. Something for which we can see the results and thus understand better how we approached engineering problems in a different time. Seeing the results of a technique allow us to understand the technique itself better.

See also - raising the Mary Rose (Tudor woodcraft and ship building), ancient railways (https://www.dailymail.co.uk/news/ar...years-discovered-10ft-underground-garden.html), etc etc.

Seeing the past in the flesh can teach us so much more than just reading about it in books.

 

If you have two pieces of plate either riveted together or held together with lacings, the two are never fully in contact except close to the fastenings. There is a gap, albeit it may be a very small one. the copper plate is subject to high temperatures on the fireside, much higher than the temperature at which it would melt. It doesn't actually get to that temperature because the copper is a good conductor and the heat is transferred to the water on the other side of the plate. However, introduce an air gap, no matter how small and you create a barrier to that heat transfer. This will result in the copper on the fireside melting or burning away in a relatively short time. This would also happen if the copper was relatively thick and is one reason why there are practical limits to how thick you can make the firebox plates. Scale on the water side of the firebox is a similar heat insulator which is one reason for washing out boilers. A similar situation would occur with steel plates but there is the added problem of corrosion between the plates forcing them apart. It is a major problem with pieces of steel that are in contact with each other. Corrosion starts in the joint and, as rust is about four times as thick as the steel that has oxidised (corroded), it forces them apart. You will often find this on cab sides where and otherwise good side has a rippled look to it around the edges where the sheet is riveted to the angle. All this is why you never plate over bad platework but always cut out the old and let in new steel.

Hope that explains why.

 

In the early days boilersmiths might use a 'dry patch' i.e rivetting a new piece of plate over the thin/cracked spot. However, this would quickly burn away for the reasons Steve gave above. It was found that a 'wet patch' was a better method where the wasted plate would be cut away behind the patch so the latter could be cooled by the boiler water and wouldn't burn away to the same extent. The wasted metal would likely be cut out by chain drilling and a cold chisel with the rivet holes drilled by ratchet drill! Some 'interesting', 'traditional' boiler repairs can be seen on several of the stored IMR locos including #3 at MOSI.
Ray.

 

Also if there is a crack present in a plate it needs to be cut away or repaired. The stress at the crack tip is high so that the crack will continue to propagate and the rate of propagation will increase as the crack gets longer. It is possible that the crack will reach a critical length and there will be a rapid failure.

 

If a crack is to be repaired, say, by grinding out and welding a hole has to be drilled beyond each end of the crack to stop it propagating.
Ray.

 

Absolutely right Ray, the crack the damage to the material carries on beyond the crack tip that is visible or detectable by NDT.

 

We've had a long discussion about welding techniques. which is fair enough. More important for those of us who aren't so technically minded is the encouraging news that apart from the need for a new inner firebox (which isn't an insurmountable problem these days), no other real "nasties" have surfaced in the dismantling and examination of 563 and some parts of the loco, including most of the bottom end, seem to be in excellent condition. In which case, once a fundraising programme has been designed and launched, a return to working order looks a distinct possibility.

I for one would be interested to see any report on the state of the engine as delivered to Swanage. We'll never know how it compared with other engines on the Kimbridge scrap line and thus whether Macleod genuinely picked the loco in the best condition, but given it must have been there for three years, from what we know so far, it appears that Eastleigh must have done quite a bit of work on at least some parts of the engine (if not the firebox) before sending it on its way to Waterloo.

 

Other than the inner Firebox, the Flour Mill have found nothing of major concern.

They have been doing a mechanical report for the SRT which is in progress and the SRT may wish to publish this in future.

 

Fascinating pictures indeed!

Welding repairs of copper fire boxes is not only limited by the technique. But to a large extent also to the copper material of the box.
Older copper plates, made before WWII quite often had too high oxygen content in the copper. (Don't ask me of the chemistry in this.) When this material is welded it becomes very brittle.
When copper was affordable again right after the war, several locomotive manufacturers built all welded fireboxes. But this was then with copper plates with sufficiently low oxygen content.

We had this tested for one of our locos, with a boiler built in Norway in 1939. The copper fire box was deemed not weldable. And eventually we sent the boiler to Swindon to have it copper fire box replaced with one in steel.

 

As its been very quite on the 563 front, whats the plan, to replace the inner box, I would imagine a like for like copper box, just out of interest, what is the price of copper these days in sufficient large size sheets to make the parts needed and who has the expertise in manipulating copper into the radius required as some sections curve more than one way are swaged in or flared out how much does the railway estimate it would have to raise to buy the plate and for an boilershop somewhere to form and rivet the bits together I would imagine its beyond Your own works capabilities and many railways, except for the likes of SDR , SVR who have specialist boiler workshops.

 

The inner box is to be completely replaced in copper. Probably talking around £60k in material.
The SRT received the initial quotation for the overhaul yesterday and representatives will travel to the Flour Mill shortly to discuss in detail. Things might seem quiet but I assure you things are moving.

 

If you need any help in putting it all back together when the time comes, I know where there is a nice 3D instruction manual









(https://collection.sciencemuseum.or...-western-railway-express-lo-locomotive-models and https://collection.sciencemuseum.or...south-western-railway-locomotive-tender-model in case you haven't come across it before - fascinating to see some of the otherwise invisible details, such as the layout of steam passages around the cylinders.).

Tom

 

I am slightly puzzled, I do know about drilling holes (to prevent crack propagation by reducing the stress concentration factor of the tip radius) but how is that possible in the repair of a cracked firebox or boiler plate....the hole will let the steam/water out......Or is the hole also welded up ?

 

It is..
Ray.

 

Thank you Ray, but could you not just grind out and weld a bit further than the very end of the crack?

 

I guess it's drilled to ensure the crack is fully prevented from further propagation. Otherwise, you wouldn't know how deep the crack went through the thickness of the plate, or whether further cracks would start from the thinned section of original plate once built back up.

Richard.

 

You would drill out as far as the sound metal, then open up the cracked material and v out the surfaces, prior to welding, then apply pre heat to treat the area to be welded the reason for going beyond the actual flaw, is because the metal will be weaker along the failure caused by the stresses on the boiler plate I remember doing a prep job with Andy Neatherwood, when we had to do such a repair we did the prep and a skilled coded welder came in to do the actual welding it was between two stay holes , and we ended up I think grinding out several either side also.

 

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Exciting news!