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1 hour ago, Niels said:

When Thompson had to do something to the crank and rail-breaking P2s he goofed,even if Ravens frontwheel B16 was a succes.

Strange.

The crank axle failures were more to do with the materials of the time and putting a lot of power down to 8 wheels, which didn't slip as readily as 6. The slipping by the Pacifics relieved much of the forces being imparted. Because the P2s didn't slip so easily, more forces were imparted to their driving wheelsets/cranks/axle, and thus metal fatigue and/or stress concentrations/poor materials did the rest. Modern materials and the excellent modern software used for design & analysis have allowed the A1 Trust to produce a new P2 fit for service on the main line.

 

Rail breaking? AFAIK there were allegations of track spreading by the original P2s, mainly in loco yards, but again modern developments have shown the new build to be acceptable to the authorities.

 

Mark

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8 minutes ago, MarkC said:

 The slipping by the Pacifics relieved much of the forces being imparted.

Rail breaking?

 

Mark

Just two points

Slipping protects steam locomotives?

Blue Peter slipped to death.

Ivatt Junior explained that many very expensive repairs were due to drivers sanding rails when slipping was violent.

Rail spreading P2s?OK?

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40 minutes ago, Niels said:

Just two points

Slipping protects steam locomotives?

Blue Peter slipped to death.

Ivatt Junior explained that many very expensive repairs were due to drivers sanding rails when slipping was violent.

Rail spreading P2s?OK?

Well yes - think about it. If you're trying to start a heavy load, you're putting a lot of force onto the driving mechanism. If the wheels start slipping, the forces opposing the driving force - ultimately the weight of the train - effectively disappear, thus the forces in the driving mechanism are much reduced, as you're only now overcoming the inertia of the wheels and internal friction. Blue Peter suffered the damage that she did because the power wasn't taken off - the regulator couldn't be closed because the steam pipe was full of water due to the boiler being overfilled and the hydraulic forces were too great to be overcome by the crew - and thus she overspeeded. It's reckoned that the wheels were rotating at the equivalent of some 140mph, and it was inertial forces that caused her damage, not the torsional forces that caused the crank axle failures on the P2s.

 

As for damage caused by sanding rails during violent slips - again, that makes sense. You have a lot of inertia (as with Blue Peter) in the wheels and motion; if you suddenly put a lot of resistance against it - by increasing the friction between wheel and rail - then damage may well result. The correct method, when a slip starts, is to shut the regulator until the slipping ceases, then apply sand if needed and open the regulator again.

 

Mark

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With regard to crank axle failures on class P2. There doesn't seem to have been an evidence of an issue with the materials used at the time, the P2 used the same crank axle design as the A3, with the latter there was no issue. As deployed on class P2, it just wasn't strong enough for the amount of torque that the locomotive could develop when accelerating a heavy train against the axle weight. There was a weakness, a sharp area that was produced in the machining of the axle key, this is where a fracture began and slowly spread each time the locomotive was working hard, until it eventually it snapped. The new P2 has a new stronger design of crank axle.

 

The pony truck on the P2 was pretty unless at doing the job it was supposed to do. When tested on the Vampire rig it lifted the front driving wheels under certain conditions. Not surprisingly, the new P2 has a new pony truck.

 

Slipping certainly can protect steam locomotives, providing the slipping is brought under control. With our own models of steam locomotives, we would expect them to slip if overloaded. If they didn't the result could possibly be terminal.

 

 

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1 hour ago, MarkC said:

The crank axle failures were more to do with the materials of the time and putting a lot of power down to 8 wheels, which didn't slip as readily as 6. The slipping by the Pacifics relieved much of the forces being imparted. Because the P2s didn't slip so easily, more forces were imparted to their driving wheelsets/cranks/axle, and thus metal fatigue and/or stress concentrations/poor materials did the rest. Modern materials and the excellent modern software used for design & analysis have allowed the A1 Trust to produce a new P2 fit for service on the main line.

 

Rail breaking? AFAIK there were allegations of track spreading by the original P2s, mainly in loco yards, but again modern developments have shown the new build to be acceptable to the authorities.

 

Mark

It's interesting how the P2s' story keeps cropping up. 

 

They did break a crank axle or two (or more) and as for 'spreading the road', I think the jury's out on this. 

 

It's true that they were restricted to certain roads in depots, though derailments on shed were not restricted to big engines. There's a picture in one of my books showing an 0-6-0T on its side on shed! 

 

I suppose in the final analysis (if ever such a thing could be applied to the P2s), I'm much more inclined to read the words of Geoff Lund, the late father of a friend of mine, who was one of the men responsible for running the P2s up to their rebuilding. There was universal dismay at Haymarket when Thompson's plans for turning them into Pacifics were announced. Eric Trask almost lost his job because of his antipathy to the project, until Peppercorn was despatched to Scotland to 'quell the revolution'! 

 

What's only recently come to light was the P2s' use on heavy, overnight troop trains as far as Newcastle during the War.  On such trains, and on the Aberdeen road, there was nothing to touch them. The men knew this, and, after they became A2/2s, they were effectively useless on the duties they'd previously handled with ease. 

 

Regards,

 

Tony. 

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Shed trackwork wasn't always the best maintained. I've seen a video of an 8F stood by a very leaky water column. There was a huge puddle around the column and the cameraman zoomed in on the tender wheels showing them on the edge of the rails.

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11 minutes ago, LNERandBR said:

. . .  the cameraman zoomed in on the tender wheels showing them on the edge of the rails.

 

Might just have needed the back-to-backs opening out a little.

;-)

 

 

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I suppose in the final analysis (if ever such a thing could be applied to the P2s), I'm much more inclined to read the words of Geoff Lund, the late father of a friend of mine, who was one of the men responsible for running the P2s up to their rebuilding. There was universal dismay at Haymarket when Thompson's plans for turning them into Pacifics were announced. Eric Trask almost lost his job because of his antipathy to the project, until Peppercorn was despatched to Scotland to 'quell the revolution'! 

 

What's only recently come to light was the P2s' use on heavy, overnight troop trains as far as Newcastle during the War.  On such trains, and on the Aberdeen road, there was nothing to touch them. The men knew this, and, after they became A2/2s, they were effectively useless on the duties they'd previously handled with ease. 

 

Tony,

 

When the overnight workings to Newcastle came to Edward Thompson’s notice he instructed the management in Edinburgh to cease these running turns.

 

Shortly afterwards Haymarket continued to use them for the Newcastle road as they were successful on it and when Edward Thompson again heard about this he sent A. H. Peppercorn up to the H.Q. in Waterloo Place Edinburgh to “read the riot act” which was a bit difficult for such a mild mannered man!

 

The above was recounted to me a couple of years ago by the late Harry Knox who served at Haymarket in the mid/late 50s then going on to a successful railway career.

 

Eric

 

(I could not figure out the "quote" set-up!)

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2 hours ago, 60027Merlin said:

I suppose in the final analysis (if ever such a thing could be applied to the P2s), I'm much more inclined to read the words of Geoff Lund, the late father of a friend of mine, who was one of the men responsible for running the P2s up to their rebuilding. There was universal dismay at Haymarket when Thompson's plans for turning them into Pacifics were announced. Eric Trask almost lost his job because of his antipathy to the project, until Peppercorn was despatched to Scotland to 'quell the revolution'! 

 

What's only recently come to light was the P2s' use on heavy, overnight troop trains as far as Newcastle during the War.  On such trains, and on the Aberdeen road, there was nothing to touch them. The men knew this, and, after they became A2/2s, they were effectively useless on the duties they'd previously handled with ease. 

 

Tony,

 

When the overnight workings to Newcastle came to Edward Thompson’s notice he instructed the management in Edinburgh to cease these running turns.

 

Shortly afterwards Haymarket continued to use them for the Newcastle rod as they were successful on it and when Edward Thompson again heard about this he sent A. H. Peppercorn up to the H.Q. in Waterloo Place Edinburgh to “read the riot act” which was a bit difficult for such a mild mannered man!

 

The above was recounted to me a couple of years ago by the late Harry Knox who served at Haymarket in the mid/late 50s then going on to a successful railway career.

 

Eric

 

(I could not figure out the "quote" set-up!)

Thanks Eric,

 

Isn't it interesting how much power the CME seemed to have over the Running Dept.? 

 

Reading Geoff Lund's notes, it seems that if a P2 were not available for a troop train, it either had to be double-headed or the train split. Either way, two locos and two sets of crew where one of each could do the job. 

 

I wonder (and am I wrong in reaching this conclusion?) that, with Thompson having his heart set on 'getting rid of the P2s', discovering how useful they were in the War effort, he didn't want anything to thwart his aim. 

 

According to Eric Trask - 'It'll take more than Edward Thompson to sack me!'. He had no time for his new CME......

 

Regards,

 

Tony. 

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1 hour ago, Tony Wright said:

Thanks Eric,

 

Isn't it interesting how much power the CME seemed to have over the Running Dept.? 

 

Reading Geoff Lund's notes, it seems that if a P2 were not available for a troop train, it either had to be double-headed or the train split. Either way, two locos and two sets of crew where one of each could do the job. 

 

I wonder (and am I wrong in reaching this conclusion?) that, with Thompson having his heart set on 'getting rid of the P2s', discovering how useful they were in the War effort, he didn't want anything to thwart his aim. 

 

According to Eric Trask - 'It'll take more than Edward Thompson to sack me!'. He had no time for his new CME......

 

Regards,

 

Tony. 

 

Afternoon Tony,


The builders of the new P2s have so far uncovered at least five crank axle failures in the P2 locomotives, it is very possibly that more are yet to come to light. Back in the day, somebody was being economical with the truth. Even by 1940s standards and without the benefits of modern testing and material, five crank axle failures, under identical circumstances, is an unacceptably high number in a class of only six locomotives. We now know that the crank axle problem was endemic to the class and was discussed with some alarm at the highest level of the LNER. The P2 was not too used on the heaviest trains. Thompson was not acting alone in restricting the use of the P2 locomotives.  Somebody had to take control of the situation, the running department were too emotionally involved or not informed enough of the problem to be making the right decision. The crank axle as designed, is totally unacceptable to be fitted to the new P2 locomotive, it will fail, possibly with hazardous consequences.

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56 minutes ago, Headstock said:

 

The crank axle as designed, is totally unacceptable to be fitted to the new P2 locomotive, it will fail, possibly with hazardous consequences.

Indeed. Which is why the A1 trust has had the design modified, to the satisfaction of the VAB and other interested parties.

 

Mark

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Thank you to all who replied to what I thought was a rather tongue in cheek query about working point rodding. It was very informative and interesting, and has made me want to take up some modelling myself. The usual two problems put me off, though - no space and no money.

 

Lloyd

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I think you have to divorce the emotion from the P2 story. The Thompson rebuilds were not especially good engines. The P2s had bags of potential but were not that good either. The new locomotive should fix the problems with the originals.

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12 hours ago, jukebox said:

 

 

I'd wager Jesse is going to chime in on that in 3.. 2.. 1... 

 

:)

 

I'm sure your stock will have a long and well appreciated after-life, Tony.

 

Cheers

 

Scott

 

Already working on it, every year I stay, he has 1 less wagon. :laugh_mini:

 

 

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10 minutes ago, Jesse Sim said:

Already working on it, every year I stay, he has 1 less wagon. :laugh_mini:

 

10 minutes ago, Jesse Sim said:

 

 

Shouldn't that be one fewer, my dear boy?

 

I'll look at the ECJS book later. Perhaps someone on here will help.

 

Regards,

 

Tony.  

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4 hours ago, Headstock said:

 

Afternoon Tony,


The builders of the new P2s have so far uncovered at least five crank axle failures in the P2 locomotives, it is very possibly that more are yet to come to light. Back in the day, somebody was being economical with the truth. Even by 1940s standards and without the benefits of modern testing and material, five crank axle failures, under identical circumstances, is an unacceptably high number in a class of only six locomotives. We now know that the crank axle problem was endemic to the class and was discussed with some alarm at the highest level of the LNER. The P2 was not too used on the heaviest trains. Thompson was not acting alone in restricting the use of the P2 locomotives.  Somebody had to take control of the situation, the running department were too emotionally involved or not informed enough of the problem to be making the right decision. The crank axle as designed, is totally unacceptable to be fitted to the new P2 locomotive, it will fail, possibly with hazardous consequences.

Thanks Andrew,

 

I'll still take the word of the men who actually were responsible for the running of the P2s - with all the locos' 'faults'.

 

Regards,

 

Tony. 

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2 hours ago, Tony Wright said:

Thanks Andrew,

 

I'll still take the word of the men who actually were responsible for the running of the P2s - with all the locos' 'faults'.

 

Regards,

 

Tony. 

 

Good evening Tony,

 

I think that it is important to look at all information that contributes to a better understanding of a subject like this. I wouldn't dismiss what the running department have to say. Thompson wasn't much of a diplomat and the total rebuilding was a mistake in my opinion. Those two things are the cause of all the bad feeling it would seem. However, there was a serious problem with the locomotives that needed addressing. As far as I can see, a new pony tuck and crank axle would do very nicely. Beyond that, the other modifications being made to the new P2 locomotive, in line with later LNER developments, will make for a better all round locomotive. The most exciting of the new additions is the adoption of the Franklin type B poppet valve gear.

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10 hours ago, Headstock said:

 

Good evening Tony,

 

I think that it is important to look at all information that contributes to a better understanding of a subject like this. I wouldn't dismiss what the running department have to say. Thompson wasn't much of a diplomat and the total rebuilding was a mistake in my opinion. Those two things are the cause of all the bad feeling it would seem. However, there was a serious problem with the locomotives that needed addressing. As far as I can see, a new pony tuck and crank axle would do very nicely. Beyond that, the other modifications being made to the new P2 locomotive, in line with later LNER developments, will make for a better all round locomotive. The most exciting of the new additions is the adoption of the Franklin type B poppet valve gear.

 

Wise words.  The impact of a broken crank axle was demonstrated when Bibby Line demolished much of Crewkerne station.  Amazing there were no casualties.  The Packets were all withdrawn from service and ultrasound testing(?) determined a number of axles were of flawed manufacture.  Meanwhile the Southern borrowed V2 locomotives.

 

Bill

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7 minutes ago, bbishop said:

The impact of a broken crank axle was demonstrated when Bibby Line demolished much of Crewkerne station.

Quite so. That could have been a very bad, high fatality, accident. At least the P2 failures were at starting/slow speed.

 

Wasn't it an L&Y Atlantic that had a bad accident after a driving wheel tyre shattered at high speed? Such failures, although thankfully rare, show that it's not just crank axles that can break.

 

Bring back the wheeltappers :)

 

Mark

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11 hours ago, great northern said:

My ability when on home turf to get poles growing out of chimneys was, as you see, effortlessly achieved at LB too. That particular pole is a photoshopping nightmare too, as it has a shelf full of locos right behind it, and they blend in with it rather well. I nearly got away with it this time, if you don't blow this up too much. That guarantees that you will, of course.

 

I think you've done a great job of cutting out the pole and insulators. I noticed some dark spots in the sky, particularly over the corner of the goods shed, around the signal on the right and generally where the models meet the sky.

 

When you're working in Photoshop one way to spot these is to grab your image and shake it. Your eye will instantly pick up any contrasting spots that are often only a few pixels but that still need to be resolved.

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37 minutes ago, Anglian said:

 

I think you've done a great job of cutting out the pole and insulators. I noticed some dark spots in the sky, particularly over the corner of the goods shed, around the signal on the right and generally where the models meet the sky.

 

When you're working in Photoshop one way to spot these is to grab your image and shake it. Your eye will instantly pick up any contrasting spots that are often only a few pixels but that still need to be resolved.

I use Paint.Net, as I couldn't get to grips with the complexities of the better programmes. Paint.Net used to allow me to put the sky layer in straight behind the original, which meant that the little blemishes showed up really well, and I could erase them with both layers in place. For some reason, an upgrade meant that I can no longer do that, so I have to go back to the main layer, and try to remember where the offending bits were. Sometimes I get bored with that, and give up. I can't bring myself to spend the time that experts like Tony and Andy Y do on a single image.

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A few thoughts on P2s and their crank axles.

 

They were the most powerful passenger steam locos in the country, hauling really heavy trains on difficult routes. 

 

To start those heavy trains, the drivers would have had to put huge amounts of power on to get them moving.

 

Under those conditions, any type of loco might have been slightly more prone to broken crank axles.

 

A heavy loco with 8 drivers is less likely to slip, which is how most locos get rid of excess power applied during starting. How many heavy trains did the P2s haul? How many crank axles broke? Maybe one or two more than you would expect compared to other classes but hardly a daily event. Did they ever cause an injury or major incident as a result of the problem? Not to my knowledge.

 

If you start to withdraw and condemn classes because of serious things that might go wrong, you would have nothing left!

 

It may even be the case that crank axles broke because of driver error, putting too much power on too quickly, rather than any fatal design flaw.

 

The very fact that the operating people were happy to use them and didn't want them to go away for rebuilding would suggest that they were not the dreadful failures that some like to make them out to be.

 

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1 hour ago, t-b-g said:

A few thoughts on P2s and their crank axles.

 

They were the most powerful passenger steam locos in the country, hauling really heavy trains on difficult routes. 

 

To start those heavy trains, the drivers would have had to put huge amounts of power on to get them moving.

 

Under those conditions, any type of loco might have been slightly more prone to broken crank axles.

 

A heavy loco with 8 drivers is less likely to slip, which is how most locos get rid of excess power applied during starting. How many heavy trains did the P2s haul? How many crank axles broke? Maybe one or two more than you would expect compared to other classes but hardly a daily event. Did they ever cause an injury or major incident as a result of the problem? Not to my knowledge.

 

If you start to withdraw and condemn classes because of serious things that might go wrong, you would have nothing left!

 

It may even be the case that crank axles broke because of driver error, putting too much power on too quickly, rather than any fatal design flaw.

 

The very fact that the operating people were happy to use them and didn't want them to go away for rebuilding would suggest that they were not the dreadful failures that some like to make them out to be.

 

 

You probably mean torque which is stressing the mechanical parts when a P2 starts off as power is the rate (energy amount per time period) at which work is done or energy converted.

 

William

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