BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

As someone who regularly has to use a six foot long torque wrench to tighten nuts to 1300Nm, I feel your pain! The breaker bar used to crack them off is about six foot as well. About 1 1/2" diameter shaft and it's interesting watching it bend when a 17 stone bloke is hanging off the end of it and the nuts still aren't coming undone!

 

What did the 17 stone bloke say when you connected a six foot wrench to his nuts? I feel his pain!

Tom

 

If upping the boiler pressure to 250psi, isnt it worth just following the Britannia spec for centre wheel set ? or are we too late for that ( Hornguides)
Also wondering, in light of the current fun and games with Tornado, its clear that the steel firebox needs to be a design specific to that - not just a copper firebox design made out of steel- and as such the grate area will be slightly reduced.
Whilst this is another nod towards fuel economy it will reduce responsiveness and perhaps its wise to keep the original cylinder dimensions after all ( i was in favour of a reduction in diameter to accommodate the increased thrust as a result of higher boiler pressure)

 

An interesting question.

 

Additonal cost for 2 differnet types of bearings, unless you nust make all 3 driven axles oversize, which is not the worst idea.

May be past design freeze already for that tho, if the wheels are already cast.

That being said 10mm on diameter (oversize) makes a huge differnce in peak stresses.

Yes, there are knock on effects to frames and hornguides. This is one of those big decisions you need to make up front before metal gets cut.

Did the Clans have any axle issues in service?

 

Far as i recall none, and a lot less prone to wheel slipping events - then but smaller cylinders and lower working pressure no doubt helped.

 

Even worse when the socket slipped!

 

Surely the Clan Project is not going down the same steel firebox path as Tornado!

https://www.theclanproject.org/design/Clan_Boiler.php

 

If they do, I’m sure it will be with eyes open, advice heeded and latest industry standard technology applied. Remember iirc they partner with organisations such as the Advanced Manufacturing arm of Sheffield Uni (apologies if I’ve got the exact details incorrect). Some other groups might wish to take note.

 

Bulleid pacifics all had steel fireboxes.
I don't think the issues with Tornado are specific to steel fireboxes per se.

 

Yes, with screwed stays.

 

Haven't welded stays been used in various other countries? AIUI the issue is in the specifics, rather than the concepts.

 

This appears to be getting very circular …. Isn’t the crux of matter still the width of the water space and inter alia the flexibility of the stays, irrespective of whether they are screwed or welded ?

 

https://www.railadvent.co.uk/wp-con...ick-Piles-boiler-at-Tyseley-Nick-Thompson.jpg

Picture proves that copper- free wide firebox boilers can be usefull if made rigth.
No flexible stays and heavy foundation ring
I just wonder what the purpose is of the big stay heads a foot or two below firehole?

 

That boiler doesn't have a conventional foundation ring. It's a light pacific boiler; they have a u-shaped foundation channel to which the inner and outer firebox plates are welded.

Tom

 

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It had been better english if I had written no flexible stays nor heavy foundation ring.
Everybody can deduct the construction from picture.
Even those that ordered the Tornado boiler .
60 years later

 

I would like to know how you can tell that the foundation ring is u shaped or solid, just from that photo alone?

 

No rivets and a row of stays in the top part of the U. Simples.

 

Thank you Steve