A4 on rail tour rescues failed diesel and coal train?

[Londontram]

Help me out here guys 

 I'm sure i can recall an incident back either in the late 1970 or very early 1980s when an A4 which I'm pretty sure was Sir Nigel Gresley while on a rail tour had to go to the rescue of a broken down diesel and it's coal train.

 I believe it was some where between Carnforth and Hellifield but my memory could be playing tricks with me.

 Mallard hadn't had her short spell on the main line, Bittern was still unrestored at the now defunct steam center in Glossop and I don't recall Union of South Africa being around at the time so am pretty sure it was SNG.

 Does anyone else recall anything about it please.

  Thanks Steve

[DavidM]

Maybe this? It's not an A4 but the only event of this kind I can think of - certainly can't think of an A4 doing it but willing to be proven wrong :-)
 

 

Dave

Edited May 21, 2020 by DavidM

[Londontram]

Thanks Dave I don't recall that one but I guess it could be my memory playing tricks but I was pretty sure the one I was thinking of was an A4.

[LMS2968]

I remember something like this, but haven't many details. A class 47 close to its load limit became a complete failure southbound climbing to Ais Gill. The rescue loco sent was a Class 25, which understandably couldn't budge that weight of train plus a dead 47 on that gradient. An A4 was heading north light engine to work a special from Carlisle. It was switched to the Up road, dropped on to the front of the 25, and then worked south as far as Hellifield before resuming its trip to Carlisle.,

[Possy92]

As LMS2968 says, it was a failed 25 and 47 on a ballast train.

 

Knew I'd heard it somewhere, scoured YouTube but eventually found a link to where I'd heard the story.

 

Have included original tweet details, but here's a pic of the event:

 

For those of you who remember the Thomas Series books, a real "Enterprising Engines" Moment!

[Ben B]

Tender-first too!  One for the "Prototype for Everything" thread?

[Rivercider]

8 minutes ago, Ben B said:

Tender-first too!  One for the "Prototype for Everything" thread?

I'm quite sure that there must have been much more tender first working over the years, but photographers then, as now, prefer to take pictures of locos working chimney first. A very unusual incident like this of course is worth recording.

 

cheers

[RJS1977]

1 hour ago, Possy92 said:

As LMS2968 says, it was a failed 25 and 47 on a ballast train.

 

Knew I'd heard it somewhere, scoured YouTube but eventually found a link to where I'd heard the story.

 

Have included original tweet details, but here's a pic of the event:

 

For those of you who remember the Thomas Series books, a real "Enterprising Engines" Moment!

 

The incident in "Enterprising Engines" was itself based on a real event, as mentioned in the foreword to the book.

 

I'm also aware of a Small Prairie rescuing a Class 37 with a stone train on the WSR, and Western Champion rescuing an HST!

[rab]

28 minutes ago, Lantavian said:

Class 25 tractive effort is 39,000 lbf (170 kN) to 45,000 lbf (200 kN)

 

Sir Nigel Gresley tractive effort is 35,455 lbf (157.7 kN)

 

So if the 25 couldn't pull the train, why could a less powerful loco pull it?

 

(NB figures are from Wikipedia. They might be right, they might be wrong)

 

 

Although the piece suggests SNG rescued the train,

in truth it was probably the combined effort of SNG

and the class 25 which acheived it.

[LMS2968]

34 minutes ago, Lantavian said:

Class 25 tractive effort is 39,000 lbf (170 kN) to 45,000 lbf (200 kN)

 

Sir Nigel Gresley tractive effort is 35,455 lbf (157.7 kN)

 

So if the 25 couldn't pull the train, why could a less powerful loco pull it?

 

(NB figures are from Wikipedia. They might be right, they might be wrong)

 

 

Incidentally, tractive effort, particularly nominal tractive effort as given in the Ian Allan ABCs and on Wikipedia, is not a measure of power output, nor is it necessarily the force that a loco can transmit to the rails.

[Bucoops]

46 minutes ago, Lantavian said:

https://www.railadvent.co.uk/2019/09/steam-locomotive-60163-tornado-comes-to-the-rescue-in-doncaster.html

 

Was thinking of this when I read this thread!

[doilum]

I once witnessed a colliery diesel "bump start" a class 25 and it's train.......

[Corbs]

44 minutes ago, Lantavian said:

Class 25 tractive effort is 39,000 lbf (170 kN) to 45,000 lbf (200 kN)

 

Sir Nigel Gresley tractive effort is 35,455 lbf (157.7 kN)

 

So if the 25 couldn't pull the train, why could a less powerful loco pull it?

 

(NB figures are from Wikipedia. They might be right, they might be wrong)

 

 

The train is being double headed, they haven’t switched the Class 25 off

[LMS2968]

Nominal tractive effort is a purely theoretical value based on the published dimensions of the loco, with a steam loco at (usually) 85% of boiler pressure. It takes no account of adhesion, so the force transmitted to the rails on a bad day might be much less than on a good dry rail. Nor can the statistics be assumed to be correct, as tyres wear and are turned down, reducing their diameter and raising the TE. Likewise, if stationary, it's possible to get 100% boiler pressure into the cylinders as the ports are open for long enough to allow this. Alternatively, much depends on the crank angle, and if bad it might not raise sufficient TE to move forward, so the driver sets back slightly so the cranks are at a better angle.

 

Once moving, the actual TE begins to decay exponentially. If speed continues to rise a point will be reached where the actual TE equals the train's resistance and that's your maximum speed.

 

The Nominal Tractive Effort takes none of this into account and many believe it's a constant value. It isn't, it changes with circumstances, especially with speed.

 

It is quite possible for a steam loco to exceed its nominal TE. I was once guard on a train from Alec Dock to Edge Hill, a notoriously stiff climb. We were well loaded and the Class 40 wasn't at all happy, with the drive mumbling curses all the way. But even I was surprised when the mumbles included, "I wish I had an 8F!" The nominal TE of an 8F is 32,440 lb., that of a 40 52,000 lb., but he reckoned that the 8 was stronger.

Edited May 22, 2020 by LMS2968

[The Stationmaster]

For info - Source BR Main Line Diesel Locomotives Diagaram Book.  Diagram DE/2000/11 (one of the two diagrams for Class 25) -

 

Maximum Tractive Effort 45,000 LB at 28.7% adhesion at 2340 amps main generator

Continuous Tractive effort 20,800LB at 17.1mph at 1300amps main generator

Rail HP at continuous rating 949HP

[Londontram]

Thanks everyone now I know I'm not loosing it totally, there is a few sparks of memory in there.

  Steve

[Steamport Southport]

I remember when the Black Five shedded at Northwich for an open day prior to Rocket 150 was put on regular freight trains. Until they were told to stop using it. Forty years ago this weekend.

 

5000. Now permanently stuffed and mounted in the NRM (or Locomotion).  

 

 

 

Jason

[Gibbo675]

9 hours ago, LMS2968 said:

Nominal tractive effort is a purely theoretical value based on the published dimensions of the loco, with a steam loco at (usually) 85% of boiler pressure. It takes no account of adhesion, so the force transmitted to the rails on a bad day might be much less than on a good dry rail. Nor can the statistics be assumed to be correct, as tyres wear and are turned down, reducing their diameter and raising the TE. Likewise, if stationary, it's possible to get 100% boiler pressure into the cylinders as the ports are open for long enough to allow this. Alternatively, much depends on the crank angle, and if bad it might not raise sufficient TE to move forward, so the driver sets back slightly so the cranks are at a better angle.

 

Once moving, the actual TE begins to decay exponentially. If speed continues to rise a point will be reached where the actual TE equals the train's resistance and that's your maximum speed.

 

The Nominal Tractive Effort takes none of this into account and many believe it's a constant value. It isn't, it changes with circumstances, especially with speed.

 

It is quite possible for a steam loco to exceed its nominal TE. I was once guard on a train from Alec Dock to Edge Hill, a notoriously stiff climb. We were well loaded and the Class 40 wasn't at all happy, with the drive mumbling curses all the way. But even I was surprised when the mumbles included, "I wish I had an 8F!" The nominal TE of an 8F is 32,440 lb., that of a 40 52,000 lb., but he reckoned that the 8 was stronger.

Hi 2968,

 

An 8F may seem stronger in certain circumstances as all of the wheels would have to slip to lose traction as they are coupled whereas a class 40 may lose traction on various axles independently and at different times making it seem less strong perhaps.

 

In support of your post:

 

The class 25 would easily get the rescued train moving but only proceed slowly. The other point to take into consideration is that Gresley pacifics have a reduced cut off in back gear and is therefore less than the full forward gear figure of 35,455lb, the A4 would simply allow for greater speed once the train is underway.

 

As for tractive effort an 08 shunt is approximately equal to an 8F at 35,000lb but the engine is rated at 350hp. last time I checked 350hp is 17.5% of 2000hp and not the 67% ratio that the tractive effort figures shew.

 

Gibbo.

[LMS2968]

Hi Gibbo,

 

I had only a vague memory of the 47/25/A4 incident, but I was pretty sure that the 25 could not budge the train at any speed, and the report seems to confirm that.

 

The comment 8F v Class 40 was the driver's, not mine, and as I said, it was a surprise to me too!

 

I knew Gresley Pacifics had a restricted cut-off, but didn't know it was more so in back gear. You learn something new everyday.

 

Yes, I know the nominal TE of an 08 and have seen them move some substantial loads. Just don't try one on a fast fitted, which the 8Fs often worked! Again, we're back to the difference between tractive effort and power output: what it will move, and how fast it will move it.

[The Stationmaster]

18 hours ago, LMS2968 said:

Hi Gibbo,

 

I had only a vague memory of the 47/25/A4 incident, but I was pretty sure that the 25 could not budge the train at any speed, and the report seems to confirm that.

 

The comment 8F v Class 40 was the driver's, not mine, and as I said, it was a surprise to me too!

 

I knew Gresley Pacifics had a restricted cut-off, but didn't know it was more so in back gear. You learn something new everyday.

 

Yes, I know the nominal TE of an 08 and have seen them move some substantial loads. Just don't try one on a fast fitted, which the 8Fs often worked! Again, we're back to the difference between tractive effort and power output: what it will move, and how fast it will move it.

Agree absolutely, a 350/08 will easily move 1,000 tons trailing on a level gradient but not very fast and I've known them shunt heavier loads than that at walking pace).    Equally they will easily move a 15 coach passenger train, including Sleeping Cars and can definitely get up to 12-15mph on level track with that load as one of ours did almost every day of the week at one of my past places of employment.  But all of that is what they were geared to do.

[rodent279]

On 22/05/2020 at 14:34, Steamport Southport said:

I remember when the Black Five shedded at Northwich for an open day prior to Rocket 150 was put on regular freight trains. Until they were told to stop using it. Forty years ago this weekend.

 

5000. Now permanently stuffed and mounted in the NRM (or Locomotion).  

 

 

 

Jason

Really? Any more info on this?

[TheSignalEngineer]

There is a story around on the web about small  prairie 4555 when it was at Tyseley following purchase for preservation. I saw it several times working freight and parcels through Snow Hill in GWR  livery in 1964. Apparently one day in August 1964 the diesel on the down Pines failed and was replaced by Modified Hall 6991. The crew requested assistance from Leamington and 4555 was sitting there after working a local freight. It was reported to have assisted 6991 up Hatton Bank and through to Birmingham.

[phil_sutters]

On 23/05/2020 at 14:59, The Stationmaster said:

Agree absolutely, a 350/08 will easily move 1,000 tons trailing on a level gradient but not very fast and I've known them shunt heavier loads than that at walking pace).    Equally they will easily move a 15 coach passenger train, including Sleeping Cars and can definitely get up to 12-15mph on level track with that load as one of ours did almost every day of the week at one of my past places of employment.  But all of that is what they were geared to do.

So this was a light load for the Osney shunter, seen while waiting for a train back to London. It would appear that the 47, with a carriage, had been sent to rescue a failed, down dmu and had itself failed, where upon the Osney sidings shunter had hauled it into the up platform.

 

[Johann Marsbar]

10 hours ago, rodent279 said:

Really? Any more info on this?

I think it would have most probably been 1978 and the loco was on display at the Depot open day - possibly something to commemorate 10 years since the end of steam.

I'll have to look through some old RM's later, but I thought it double headed a scheduled freight through the area as a pre-planned part of the event - was it the ICI hoppers???

[ColinK]

Yes it was at the depot open day. I can’t remember the date though.