Cutoff to brake steam engine

[Corbs]

On 16/03/2019 at 13:26, Guy Rixon said:

Reversing the engine for emergency braking was common in the 19th century. A lot of the accident-investigation reports read like "on seeing the obstruction, the driver reversed his engine but was unable to stop in time". (Note the selection effect: where the driver did manage to stop by reversing the engine there was no enquiry and we don't hear of the incident.)

 

I think in this instance, being chased down by a Spitfire and having to make a sudden stop constitutes just such an emergency...

 

(what do you mean it's not real?!)

 

On 18/03/2019 at 18:30, Gibbo675 said:

 

Either full forward or full back gear at speed will certainly not do a locomotive any good in either direction with the regulator open, try putting a car into first gear or even reverse at 60 mph and see how that ends up.

 

 

In a past life a guy I knew was racing his Pulsar VZ-R (Japanese, high revving 1.6 litre). Redline in 1st, 2nd, went to go into 3rd, missed and selected 1st at about 70mph and 7,200rpm. Bang, pow, and a lot of smoke was the result.

When he opened the engine up a few months later, the pistons looked like they were made of chocolate! 

[The Johnster]

5 hours ago, Ruston said:

I'm curious as to the type of railway, and period, that you are modelling to need to consider this. What wagons are you running that have no brakes?

I think what he means is brakes that can be applied from the locomotive when the train is in motion; all wagons have handbrakes of course.  Unfitted or part fitted freight trains ran for another couple of decades after the end of steam, and any steam era layout can feature them.  Once in motion with an unfitted train, the only control was from the loco and the brake in the guard's van, which is why such trains were limited to 25mph in speed.

[Phil Bullock]

Always enjoy prototype operational discussions!

 

Afraid my contributions are limited to what I have read but the following may be of interest in the light of some of the above points -

 

Winding a loco in to reverse gear when running forwards - quoting Tangmere is interesting, Peter Smith in his S&D books quotes Spam Can 34043 Coombe Martin - the roughest loco at Bournemouth Central allegedly, regularly foisted on to S&D turns as they didnt want it on the main line - as tearing in to its train with gusto going forwards - when the gear, according to the indicator, was in 7% reverse! A bit of slack in the Bulleid chains perhaps?

 

As for using the loco hand brake to control trains - Tony Barfield describes this on 57xx panniers at Kidderminster , to bring unfitted wagons together, when working heavy trains from Kidder yard down to the sugar beet factory at Foley Park. More "feel" to it than the loco steam brake...

 

And re the Lada incident - a school friend tried putting a MK1 Excort Mexico we had collected from Nottingham in to reverse at 60 to show me how good the clutch and gear box were. Not for much longer - had to be towed through Bham by the accompanying Mini back to Worcester. Mechanical sympathy in short supply there!!!

 

Phil

[Ruston]

8 hours ago, The Johnster said:

I think what he means is brakes that can be applied from the locomotive when the train is in motion; all wagons have handbrakes of course.  Unfitted or part fitted freight trains ran for another couple of decades after the end of steam, and any steam era layout can feature them.  Once in motion with an unfitted train, the only control was from the loco and the brake in the guard's van, which is why such trains were limited to 25mph in speed.

Well, not all wagons had hand brakes. Lots of wagons in the 19th century didn't and contractors side-tipping wagons never had them, even the same type when used into the 1960s in industry, hence my asking. With unfitted trains where the wagons did have handbrakes, wasn't the practice to stop and pin down as many brakes as required before setting off down gradients where the locomotive and brake van weren't enough, so there was no need to be putting engines into reverse on the move anyway?

[roythebus]

Yes, but only usually where mentioned in the Sectional appendix.

[The Johnster]

What we called 'incline working' in South Wales; the idea was to pin down brakes as the train set off slowly down the bank until the driver whistled that he had enough and could control the train by pulling gently against the resistance of the brakes.  The number of wagons needing to be braked, the potential overconfidence of the driver, differing rail conditions and the strength which had been used to pin the brakes were all movable feasts, and the provision of sand drags and piles of mangled wagonry at the bottom of inclines proved it (nerves of steel, we 'ad boyo, nerves of steel).  Strangely, the spilled coal never seemed to be there the following day...

 

Contractors wagons are not designed for use at anything more than the slowest of speeds and should not be used on a railway open to normal traffic.  Only in the very early days did wagons not have any brakes at all, and were secured by 'scotches' or chocks, and they were not allowed to be worked on running lines without brake vans with guard's in them.  On heavy passenger trains there were several brake vans, all with guards the senior man in the rear vehicle, and the driver whistled for braking assistance.  The Armagh disaster put the final coffin nail into this practice; fail safe automatic brakes capable of being worked from the locomotive were required after this avoidable tragedy.

 

Freight vehicles followed very slowly.  Express freight timings and the requirement to attach them to passenger trains as tail traffic meant that some were vacuum braked even back then, but the adoption of automatic brakes took another 100 years to be universal.  A major obstacle to progress was the coal industry, in both it's private and nationalised forms, which resisted any form of vehicle other than the unfitted 9' wheelbase mineral wagon as strenuously and for as long as it could, despite the railways' offering reduced rates for higher capacity wagons.  Their shunters liked using 3-link couplings and found vacuum pipes got in the way, and the siding capacity and spacing of the loading chutes in the washeries at the pits made the standard 7 planker and it's steel 16ton replacement difficult to eradicate.  The MGR method went some way to modernising things, but I was still working unfitted or part fitted trains in the 70s, almost all the unfitted wagons being coal.

 

Modern train are all continuously and fully fitted with fail safe automatic air brakes, and mostly run in fixed rakes that reduce the need for shunting.

[The Stationmaster]

10 hours ago, Phil Bullock said:

Always enjoy prototype operational discussions!

 

Afraid my contributions are limited to what I have read but the following may be of interest in the light of some of the above points -

 

Winding a loco in to reverse gear when running forwards - quoting Tangmere is interesting, Peter Smith in his S&D books quotes Spam Can 34043 Coombe Martin - the roughest loco at Bournemouth Central allegedly, regularly foisted on to S&D turns as they didnt want it on the main line - as tearing in to its train with gusto going forwards - when the gear, according to the indicator, was in 7% reverse! A bit of slack in the Bulleid chains perhaps?

 

As for using the loco hand brake to control trains - Tony Barfield describes this on 57xx panniers at Kidderminster , to bring unfitted wagons together, when working heavy trains from Kidder yard down to the sugar beet factory at Foley Park. More "feel" to it than the loco steam brake...

 

And re the Lada incident - a school friend tried putting a MK1 Excort Mexico we had collected from Nottingham in to reverse at 60 to show me how good the clutch and gear box were. Not for much longer - had to be towed through Bham by the accompanying Mini back to Worcester. Mechanical sympathy in short supply there!!!

 

Phil

The original Bulleid pacifics were notorious for the  cut-off gear indicating something veery different from what was actually happening in the valve gear.  Allegedly due to the steam reverser which according to some had a mind of its own  according to people I know who worked on them in SR(egion) main line steam days.

 

I can understand a reluctance to use a steam brake as some enginmen had the feeling - from tales of many years earlier - that the brake needed time to 'warm up' to be effective, one reason the GWR used vacuum brakes on it larger engines because a collision occurred when the steam brake was slow to act.

 

On incline working the name of the game was to get the entire train almost immovable by pinning down sufficient brakes to hold it stationary with the brakevan and engine brakes completely released - this process was ideally started where there was no falling gradient although in some cases the marker board to apply wagon brakes might be on a slightly falling gradient.  As the train drew forward onto the falling gradient more wagon brakes were appllied as necessary to keep the train under control until the Driver was satisfied that sufficent brakes had been applied to allow the train to be safely controlled and speed kept down to little more than walking pace.  The engine was then pulling against the brakes to get the train moving and in theory if it ceased to pull the train would slow with little need for the engine to brake other than for finally bringing the train to a stand.  The reality of course could be rather different,  I once travelled on a train doing 40mph while being worked to the Incline Instructions and the only reason it stopped was because it ran out of steep falling gradient - the engine brakes were hardly applied at all because the brake blocks wouldn't have lasted very long (but it dd stop in the right place).

[Gibbo675]

10 hours ago, Phil Bullock said:

Winding a loco in to reverse gear when running forwards - quoting Tangmere is interesting, Peter Smith in his S&D books quotes Spam Can 34043 Coombe Martin - the roughest loco at Bournemouth Central allegedly, regularly foisted on to S&D turns as they didnt want it on the main line - as tearing in to its train with gusto going forwards - when the gear, according to the indicator, was in 7% reverse! A bit of slack in the Bulleid chains perhaps?

 

Phil

Hi Phil,

 

Allow me to dispel some myths, Bulleid valve gear is very difficult to set up but once it is set up it is very easy to retain its setting unless new valve liners are fitted. As for the chains running slack this is partially nonsense as the chains are Morse type chains and when slack they run on the outer ends of the teeth of the sprockets which retains the timing function of the chain. Morse type chains are, or at least were, used for the timing chains of internal combustion for that very reason.

 

I would suggest that 34043 had its sprockets misaligned when the horizontal chain was connected on the setting of the valves. This is quite easy to do as all of the backlash has to be accounted for when connecting the chain. There is also the matter that the valve does not move when cogging the sprockets for four teeth when establishing front dead centre. If this had happened at shopping then the lead function would be in the wrong place and cause the engine to work better "inside out" so to speak.

 

During a frantic all nighter, I once managed to put Tangemere's chain on 180* out of sync and the locomotive did run but was quite loud and struggled to pull its own tender. How we laughed at having to slide around an oily connecting rod to reset it all !

 

Gibbo. 

[Gibbo675]

12 minutes ago, The Stationmaster said:

The original Bulleid pacifics were notorious for the  cut-off gear indicating something veery different from what was actually happening in the valve gear.  Allegedly due to the steam reverser which according to some had a mind of its own  according to people I know who worked on them in SR(egion) main line steam days.

Hi Mike,

 

The primary cause of false readings given by Bulleid reverser scales is that should the oil level in the locking cylinder drop then its ability to hydraulically lock the valve gear into position is lost. The other problem connected with this situation is that the valve gear may jump about while the locomotive is under power giving rise to all sorts of cut off positions either every revolution of the wheels or in a harmonic relative to the revolution of the wheels.

Half a pint of steam oil and a nip of the gland nuts sorts them out, but that requires climbing up under the boiler just ahead of the fire box.

 

Gibbo.

[LMS2968]

44 minutes ago, The Stationmaster said:

The original Bulleid pacifics were notorious for the  cut-off gear indicating something veery different from what was actually happening in the valve gear.  Allegedly due to the steam reverser which according to some had a mind of its own  according to people I know who worked on them in SR(egion) main line steam days.

 

I can understand a reluctance to use a steam brake as some enginmen had the feeling - from tales of many years earlier - that the brake needed time to 'warm up' to be effective, one reason the GWR used vacuum brakes on it larger engines because a collision occurred when the steam brake was slow to act.

 

On incline working the name of the game was to get the entire train almost immovable by pinning down sufficient brakes to hold it stationary with the brakevan and engine brakes completely released - this process was ideally started where there was no falling gradient although in some cases the marker board to apply wagon brakes might be on a slightly falling gradient.  As the train drew forward onto the falling gradient more wagon brakes were appllied as necessary to keep the train under control until the Driver was satisfied that sufficent brakes had been applied to allow the train to be safely controlled and speed kept down to little more than walking pace.  The engine was then pulling against the brakes to get the train moving and in theory if it ceased to pull the train would slow with little need for the engine to brake other than for finally bringing the train to a stand.  The reality of course could be rather different,  I once travelled on a train doing 40mph while being worked to the Incline Instructions and the only reason it stopped was because it ran out of steep falling gradient - the engine brakes were hardly applied at all because the brake blocks wouldn't have lasted very long (but it dd stop in the right place).

Of course, it could also work the other way and the driver called for too many brakes to be pinned. There were occasions when a train stalled going down an incline as the engine was unable to overcome the excessive brake force of the extra braked wagons.

[The Johnster]

2 hours ago, The Stationmaster said:

The original Bulleid pacifics were notorious for the  cut-off gear indicating something veery different from what was actually happening in the valve gear.  Allegedly due to the steam reverser which according to some had a mind of its own  according to people I know who worked on them in SR(egion) main line steam days.

 

I can understand a reluctance to use a steam brake as some enginmen had the feeling - from tales of many years earlier - that the brake needed time to 'warm up' to be effective, one reason the GWR used vacuum brakes on it larger engines because a collision occurred when the steam brake was slow to act.

 

On incline working the name of the game was to get the entire train almost immovable by pinning down sufficient brakes to hold it stationary with the brakevan and engine brakes completely released - this process was ideally started where there was no falling gradient although in some cases the marker board to apply wagon brakes might be on a slightly falling gradient.  As the train drew forward onto the falling gradient more wagon brakes were appllied as necessary to keep the train under control until the Driver was satisfied that sufficent brakes had been applied to allow the train to be safely controlled and speed kept down to little more than walking pace.  The engine was then pulling against the brakes to get the train moving and in theory if it ceased to pull the train would slow with little need for the engine to brake other than for finally bringing the train to a stand.  The reality of course could be rather different,  I once travelled on a train doing 40mph while being worked to the Incline Instructions and the only reason it stopped was because it ran out of steep falling gradient - the engine brakes were hardly applied at all because the brake blocks wouldn't have lasted very long (but it dd stop in the right place).

Nerves of steel.

[The Johnster]

2 hours ago, LMS2968 said:

Of course, it could also work the other way and the driver called for too many brakes to be pinned. There were occasions when a train stalled going down an incline as the engine was unable to overcome the excessive brake force of the extra braked wagons.

This was, of course, much less exciting...

 

Seen this happen with a 37 at Penrhos.

[The Johnster]

2 hours ago, LMS2968 said:

Of course, it could also work the other way and the driver called for too many brakes to be pinned. There were occasions when a train stalled going down an incline as the engine was unable to overcome the excessive brake force of the extra braked wagons.

This was, of course, much less exciting...

 

Seen this happen with a 37 at Penrhos.  There was a sort of balance to be aimed for with this, between pinning down as few brakes as you needed, but hard, so that the job was done more quickly and picking them up at th

[The Stationmaster]

18 hours ago, The Johnster said:

Nerves of steel.

No need to worry if, coming down from Cwmbargoed, you passed through Bedlinog no faster than 40 mph as that was slow enough to ensure you'd stop at the bottom.

 

Never have my eyes been so tightly focussed on a speedo on diesel than coming down there.  Far more 'exciting' than getting a double yellow at 95mph on the Up Main Line at Burnham when working a commuter set overdue for brake blocks

[The Johnster]

Did it one time, on a rest day with a Radyr guard who'd agreed to show me what real railway work was about.  Different world up there.  40 through Bedlinog sounds about right right but knowing what was ahead and how soon we'd be there, stopped or not, made it feel a lot faster!  On the front, with 800 tons of train behind you, it must have sharpened your reflexes considerably...

 

I reckoned you could survive abandoning ship at 40, albeit with injuries, provided there was enough space where you landed to tuck and roll, but any more than that and you'd committed yourself to your fate and were probably better off in the van on the basis that the train would absorb most of the initiial shock.  The Radyr guard seemed to accept that the train was running normally, despite the fact that it was clearly not under anything but the most loose description of the meaning of being under control, and this re-assured me, but I won't try to convince anyone that I felt particularly confident about the potential outcome.  We pulled up with no problem at Ystrad Mynach of course, just as if this sort of knife edge avoidance of disaster happened on a daily basis (which of course it did).

 

Gave me a measure of respect for Radyr men and Valley working in general; Canton didn't have any work anything like this, although coming down from Llanvihangel on the up could be a bit hairy.  Our only Valley turn in the freight links at Canton was the daily Pontypridd Parcels, hardly pushing the envelope with a Hymek and 4 BGs or GUVs, but it was nice to shunt into the lovely Brunel goods shed at Ponty.  I also worked a couple of fully fitted road salt trains; these would turn up every autumn from the salt mines in Cheshire to fill local council orders for winter gritting, the stock being wooden 5 plank opens as the salt would have corroded steel opens.  Pontypridd once and Aber Jc once, both with 37s and a Radyr pilot on the Aber job as I didn't sign Penrhos (despite knowing in very well from my enthusiast days) but again hardly 'incline working'!

Edited March 21, 2019 by The Johnster

[avonside1563]

It was quite common to see Industrial locos braked on the reverser, with slide valves there is far less chance of over compressing the cylinders and with some judicious use of the drain cocks a good degree of sensitivity can be obtained. At Foxfield we have two locos that we often 'Pole' to stop, Robert Heath No.6 and Bellerophon. Neither of these locos had steam brakes fitted until preservation and I doubt the colliery drivers would have bothered leaping around the footplate on Belle as the handbrake is on the opposite side to the reverser. If you want to try the ultimate in controlling a train try an unfitted rake of wagons on a loco with a mediocre handbrake on a 1 in 19 gradient. Come to that, try it on a loco with a good brake on a wet rail.....

 

The difference between driving styles of different modes of steam transport are interesting as most traction engines and steam rollers are controlled on the reverser, the handbrake on many only being used as an additional menas of retardation. Reaction times in modern traffic mean it is much quicker to pull the reverser into back gear and flick the regulator open when some numpty cuts in front of you in traffic! If you go for the handbrake you will probably end up flattening the back of their car...

[Beatty 139]

On 16/03/2019 at 12:33, Gordon A said:

The steam brake on a shunting loco would be the brake to use, quick to apply and quick to release.

Using the reverser would be a no no as LMS2968 explained.

The hand brake is only good for parking a static loco. To slow to apply and not enough force.

On the industrials I have driven you want at least 100lbs showing on the clock, preferable a bit more.

A lot of industrial loco’s especially older/smaller ones 10”/12” cylinders only had hand brakes and no steam brakes, also quite a few of the smaller bellow 20T industrial diesels were hand brake only. 

Just have to be handled with care and kept well adjusted.

[jim.snowdon]

Compression braking is quite normal on some mountain rack railways, albeit that additional measures such as water injection (to avoid the cylinders getting too hot) are usually designed in.

 

Jim

[pH]

On 19/03/2019 at 18:11, The Johnster said:

 Once in motion with an unfitted train, the only control was from the loco and the brake in the guard's van, which is why such trains were limited to 25mph in speed.

 

You might (or might not) like to read David L. Smith's accounts of the working of the unfitted overnight goods from Glasgow to Stranraer in Glasgow and South Western and early LMS days, over the section of line between Maybole and Girvan. The gradient profile looks like a roller coaster, and in the first years of the LMS, the goods  could load up to 80 wagons and was double-headed, with one brake van. The problem was to keep the couplings tight through the dips, which was done by going fast down the preceding hill with the guard braking hard, in the hope that the train would still be stretched out at the bottom. One of the engines sometimes used as the train engine had a speedometer, and it was seen to be showing 70MPH on occasion! 

 

Smith also tells of this train having to be stopped in a hurry one night, and the driver of the pilot reversing his engine to stop it.

[The Johnster]

A similar situation pertained (though not with 80 wagons and admittedly a much shorter section) between Newport and Hereford on the North to West line, particularly between Pontypool Road and Abergavenny, and the technique was, like the Port Road, to keep power on to keep the couplings tight, but the matter is complicated by the vertical radii of the dips and summits.  From St Julian's in Newport to Pontrilas there is no level stretch of track.  These frequent dips and summits mean that the wagons are compressed at the bottom of the dip and the drawhook springs pulled out to the limit over the summits, and it is very difficult for even a skilled driver with the guard doing his best with the van brake to avoid a 'snatch' in the dips, slight at the locomotive end but quite violent in the van  Speed built relentlessly the further you went and over 60 (with a train limited to 45mph) was not unusual at Penpergwm, where the line crosses the river Usk before beginning the climb to Abergavenny and Llanvihangel, the ruling gradient.

 

This spot is blacker than the inside of a cow on a dark night (I imagine much of the Port Road was like this) and prone to mist; it's easy to get lost and disorientated and you have to keep your wits about you.  The old station building at Penpergwm was owned by an ex railwayman in the 70s, though, and he would leave the lights on in his front room to assist us.

[LMS2968]

Similar the Whelley line around Wigan, which I've mentioned before. It was a bank engine route, and the banker kept steam on on both the rising and falling gradients, the train engine supplying just enough power to keep the train moving uphill. In this way the buffers were (mostly) kept compressed from start to finish.

[pH]

Minor point - the Port Road was Dumfries to Stranraer. The train Smith was writing about ran Glasgow-Ayr-Girvan-Stranraer.

[The Johnster]

I stand corrected.