Tornado fails on ECML

[Bon Accord]

You don't coast in mid gear on a steam loco. On one fitted with Walschaerts gear coasting is at typically 50-55% cut off, although can come down to around 40% . On some locomotives the correct position is marked on the reverser drum/ indicator with a 'D' (drift').

 

 

You do if your locomotive is fitted with Trofimov modified Walschearts gear. After shutting off you immediately wind out to full forward gear, then once steam chest pressure is zero (which is normally about the time taken to get her out to 65-70%) you wind back to mid gear and leave it there until coming to a stop.

During this process the valve heads move on the spindle towards each other leaving the valve ports open, the rough idea being that there is less friction when coasting to a stop.

Prior to moving after the stop and whilst still in mid gear you quickly open and close the regulator to reset the valves to the extended position (a loud thump is heard from the for'd end) and then wind out to full forward ready for the off.

A design seen on the continent and Eastern Europe/Russia, but I don't think it was ever seen on these shores - I could be wrong however..

 

[Bon Accord]

That's probably why many of the Polish loco's get knackered so quickly, except for OL49 69 I think it is that has 'special valves' and you leave it at the cut off it was working at until it slows right down.

P

 

OL49-59 has Trofimov gear, 7 and 69 have conventional Walschearts valve gear where you normally wind out to 65% forward gear when coasting. I can't remember the numbers of the other Trofimov locomotives however.

[royaloak]

Lack of lubrication could lead to failure at any speed. However, the faster two parts are "rubbing" with little or no lubrication, then the greater the friction and heat generated which leads to failure more quickly. The photo of the broken valve gear components on the track showed considerable heating had affected one of them, either through heat transfer from the valve and spindle, or from lack of lubrication to the pivot (although I would find that rather more surprising).

That heating would have been caused by the bending of it ( the combination lever) by the forces it endured when the valve spindle seized and the crosshead and union link kept moving. 

Edited April 22, 2018 by royaloak

[rodent279]

That heating would have been caused by the bending of it ( the combination lever) by the forces it endured when the valve spindle seized and the crosshead and union link kept moving.

That is exactly what I thought when I saw the photo of the remains lying on the track. Repeated bending caused by the valve being seized has heated the rod, and eventually it has failed.

[jamie92208]

Just out of interest as we are discussing a lubrication problem on the piston valve/valve spindle.   Can anyone one tell me how this area is lubricated.  Does it come  via an atomiser to be carried along with the inlet steam or does it come via the displacement lubricator.   I thought that pistons and valves needed steam for lubrication so steam locos were often in light steam when being towed.

 

Jamie

[roythebus]

Going back to post 275 about the DMU with alleged speed related failure, diesel engine are governed to a certain speed for  good reason! Most "traction" and "bus" small diesels (typically up to about 12litre) will run happily at about 2500rpm. Much above that they tend to do silly things like drop valves.

 

I've attended to 2 RT buses (with the old AEC 9.6 litre engine which runs at 1800rpm) which have not dropped valves, but had the thimbles that go on top of the valves actually fall off. I've been told this is caused by over-revving. Luckily the cylinder head is designed that the valve thimble doesn't disappear into the abyss but tends to sit inside the cylinder head. One was in a client's premises in Germany, where we were running the engine up to test it for excess smoke. It suddenly started making an awful noise.. The second was a few weeks later when another client in Kent said his bus was making an awful noise. He drove it over to my place and what I thought hd happened had happened. Dropped the valve thimble. Simple fix, had the same problem 2 weeks ago in Germany.

[Titan]

Just out of interest as we are discussing a lubrication problem on the piston valve/valve spindle.   Can anyone one tell me how this area is lubricated.  Does it come  via an atomiser to be carried along with the inlet steam or does it come via the displacement lubricator.   I thought that pistons and valves needed steam for lubrication so steam locos were often in light steam when being towed.

 

Jamie

 

It is usually a mechanical lubricator that pumps a set amount of oil per revolution in to the steam line. If there is no steam there is nothing to carry the oil to the valves and cylinders, hence the requirement for locos being in light steam when towed.

 

What is a little concerning is that since the steam line feeds all three cylinders, if one valve was not getting any oil then neither were the others...

[jjb1970]

My experience is that three failures modes dominate machinery failures, maloperation, poor alignment and poor lubrication. 

[LMS2968]

LMS practice, and possibly the same on the A1. One mechanical lubricator would feed oil for two cylinders to the atomiser, where the live steam was introduced. This then fed the steam / oil through individual pipework to check valves at the point of delivery: each valve head, middle of cylinder and piston rod where it entered the cylinder. The check valves prevented the oil syphoning back to the atomiser while the engine was standing, so lubrication was available as soon as the engine began to move. A fault in one delivery pipe or check valve would not effect any other component.

[Mallard60022]

It is usually a mechanical lubricator that pumps a set amount of oil per revolution in to the steam line. If there is no steam there is nothing to carry the oil to the valves and cylinders, hence the requirement for locos being in light steam when towed.

 

What is a little concerning is that since the steam line feeds all three cylinders, if one valve was not getting any oil then neither were the others...

Not on Tornado matey.

Phil

[Dr Gerbil-Fritters]

You do if your locomotive is fitted with Trofimov modified Walschearts gear. After shutting off you immediately wind out to full forward gear, then once steam chest pressure is zero (which is normally about the time taken to get her out to 65-70%) you wind back to mid gear and leave it there until coming to a stop.

During this process the valve heads move on the spindle towards each other leaving the valve ports open, the rough idea being that there is less friction when coasting to a stop.

Prior to moving after the stop and whilst still in mid gear you quickly open and close the regulator to reset the valves to the extended position (a loud thump is heard from the for'd end) and then wind out to full forward ready for the off.

A design seen on the continent and Eastern Europe/Russia, but I don't think it was ever seen on these shores - I could be wrong however..

 

At least two D10 Directors based at Northwich had Trofimoff piston valves... Prince Henry and Edwin A Beasley.  They are mentioned in the Xpress Publishing book British Railways Operating History, volume two, Motive Power Chief by A J Somers.  Page 33 to be precise, although he refers to them as Tropimov valves.  Presumably he heard rather than saw the name.

 

They also get a mention here on the LNER Encyclopedia, quote:

 

'During the 1930s, a number of D10s were experimentally fitted with Trofinoff (sic) Automatic By-pass (T.A.B.) piston valves. When pressurised with steam, these valves acted like conventional piston valves. When the steam was shut off, the heads were free to drift. This was to avoid the compression of air when coasting, and to allow for freer running. The former GCR main line over the Pennines was noted for its long gradients, so these locomotives were a good choice for the experiment. Six D10s were fitted with the T.A.B. valves between 1935 and 1938. The trials appear to have been a success, but they were interrupted by World War 2.'

 

More about them here.

 

Edited April 23, 2018 by Dr Gerbil-Fritters

[jamie92208]

Not on Tornado matey.

Phil

 

​​I suppose that my question should actually been phrased along the lines of "What are the lubrication arrangements for the centre cylinder and it's valves."

 

Jamie

[Mallard60022]

​​I suppose that my question should actually been phrased along the lines of "What are the lubrication arrangements for the centre cylinder and it's valves."

 

Jamie

Can't explain Jamie but the decision was made during construction to provide better lube supply than on the originals and after a lot of early runningof 163 even that was upgraded IIRC. I'm sure someone with more hands on experience of the machine itself would be happy to let you know. I'd like to know allsorts of things too as it really interests me how these things work.

I wonder if, in these microchip days, it could be possible to fit some sort of device that would detect such a problem, as happened last week, in the future.

Motor cars have an array of warning circuits and Tornado is a damn sight more valuable than (say) my poxy Vauxhall. 

Sincerely, Phil

Edited April 23, 2018 by Mallard60022

[Dr Gerbil-Fritters]

I wonder if the Advanced Super Tornado would have had a similar problem?  Alas, we will never know.  

[Mallard60022]

I wonder if the Advanced Super Tornado would have had a similar problem?  Alas, we will never know.  

Oh ta, I've never seen that.

Phil

[Revolution Ben]

 

Hello all,

 

I am not sure if this is of interest but I happened to be at the Nene Valley Railway at the weekend and noticed Tornado. It's one of the few steam locomotives I can identify!

 

Looking at the front, it appears that the cylinder front covers (?) have been removed - and maybe the pistons inside too? Also, a part on the coupling rod assembly appears to be hanging down.

 

 

I would be grateful if anyone could give a more informed insight as to what is being done.

 

Cheers

 

Ben A.

[APOLLO]

My experience is that three failures modes dominate machinery failures, maloperation, poor alignment and poor lubrication. 

 

Too true.

 

My dad (in respect of his car) had a saying --  "oil is cheaper than bearings"

 

Brit15

[Titan]

Hello all,

 

I am not sure if this is of interest but I happened to be at the Nene Valley Railway at the weekend and noticed Tornado. It's one of the few steam locomotives I can identify!

 

Looking at the front, it appears that the cylinder front covers (?) have been removed - and maybe the pistons inside too? Also, a part on the coupling rod assembly appears to be hanging down.

 

IMG_1883.JPG

 

I would be grateful if anyone could give a more informed insight as to what is being done.

 

Cheers

 

Ben A.

 

I expect that as a precaution all valves and pistons are being thoroughly examined, possibly with the other valves being removed for inspection also. The bit hanging down appears to be the union link, the other end of which connects to the combination link which has been removed on this side.

[Nimbus]

LMS practice, and possibly the same on the A1. One mechanical lubricator would feed oil for two cylinders to the atomiser, where the live steam was introduced. This then fed the steam / oil through individual pipework to check valves at the point of delivery: each valve head, middle of cylinder and piston rod where it entered the cylinder. The check valves prevented the oil syphoning back to the atomiser while the engine was standing, so lubrication was available as soon as the engine began to move. A fault in one delivery pipe or check valve would not effect any other component.

 

The front end of the centre valve spindle on the A1, which is reported to be the site of the seizure, appears to have a direct oil feed. The opening seconds of this pre-departure video shows the pipe and union quite usefully.

Thinking of the scars my car has received from airborne debris, I wonder how similarly vulnerable the A1's arrangement is?

[jim.snowdon]

The front end of the centre valve spindle on the A1, which is reported to be the site of the seizure, appears to have a direct oil feed. The opening seconds of this pre-departure video shows the pipe and union quite usefully.

Thinking of the scars my car has received from airborne debris, I wonder how similarly vulnerable the A1's arrangement is?

To be correct, the Al website reports the seizure as having occurred between the front valve and the liner. There are four points along the length of the piston valve that require lubrication - the bush that carries the front end of the valve spindle, the oil feed to which is what you can see at the front ofthe engine, the piston rings where each of the two valve heads run in their respective sleeves, and the bush at the tail (rear) end of the valve spindle.

The valve head piston rings run at steam chest pressure and are generally lubricated, like the piston itself, by oil introduced into the steam flow; the two bushes are normally at no more than exhaust pressure and can be lubricated by direct oil feeds, which is what the fitting and pipework visible at the front ofthe engine will be for.

 

Jim

[LMS2968]

As Jim Snowdon says, that feed is to the spindle only at the front. The engine has inside admission valves, so this area is not subject to superheated steam temperatures or pressures, only those at exhaust. The atomised oil feed to valve heads will be by a mechanical lubricator mounted remotely from the steam chest and driven by a take-off from the outside valve gear..

[rodent279]

Too true.

 

My dad (in respect of his car) had a saying -- "oil is cheaper than bearings"

 

Brit15

He is not wrong. I change oil every 3000 miles, which is probably overkill, but oil is cheap, and easy to replace, engines are just the opposite.

[Titan]

He is not wrong. I change oil every 3000 miles, which is probably overkill, but oil is cheap, and easy to replace, engines are just the opposite.

 

Perhaps if you did not use cheap oil you would not need to change it so frequently. I use quality branded oil which is not cheap, and at the recommended service interval of 12,000 miles. No sign of engine wear at all at 130,000 miles, which means  that by the time the car is of no further use the engine will still be going strong. And I bet the oil cost is far less than 4x the one you are using!

 

These days when engines last so long anyway, too frequent servicing is literally money down the drain. Or at least down the responsible means of disposal...

 

Not only that, but when doing 20,000+ miles a year, I really did not fancy having the oil changed every six weeks or so....

[jjb1970]

I wonder if the Advanced Super Tornado would have had a similar problem?  Alas, we will never know.  

 

A shame it wasn't built. I don't want to urinate on anybody's fire and I do understand the tremendous achievement of those building these replicas but I just can't really get excited about them in a way I would if they implemented the ideas of engineers like Porta and Wardale to see what steam locomotives could achieve if utilising modern design and manufacturing capabilities. The outcome would still be to confirm that the conventional steam locomotive was woefully inefficient and obsolete but it'd be fascinating to see just what could be achieved.

[jjb1970]

On oil, the most oil guzzling engines I ever saw by a long way were Detroit high speed diesels, V16's with twin turbo' and roots blowers running at 1800rpm. Very highly blown and with a very high power/weight ratio but equally problematic, extremely noisy and they drank oil at a frightening rate, ghastly things. The company I worked for tried increasing the oil change interval to something halfway approaching reasonableness but gave up when the things started blowing up as a result.