PTA/JTA/JUA, By Accurascale (NOW WITH ADDED BSC INNERS!)

[Accurascale Fran]

34 minutes ago, mevaman1 said:

Look what has just come up on FB!  50149 on a train of JUAs and PGAs.  I know it was for the adhesion trials but there is a prototype for everything.  Photo courtesy of Richard Holmes.

excellent, I have a resprayed 50149 ready to go too! Great pic!

 

Cheers!

 

Fran

[GordonC]

22 minutes ago, Fitzer said:

I never saw that freight sector division livery before, or a 50 in rail freight livery for that matter either.

 

Railfreight General sector - only a handful of locos ever received it. Only 50149 and 50117 (once in preservation) carried it

[BR Blue]

21 minutes ago, Fitzer said:

I never saw that freight sector division livery before, or a 50 in rail freight livery for that matter either.

50049 was renumbered to 50149 and carried the livery for a year in 1987 to 88 from memorry. It was then renumbered back to 50049 and repainted to NSE. It was a trial to see if they could use 50s on freight. The livery was also done later on some preserved locos.

[mevaman1]

This from Pip Dunn on FB.

 

Today’s OTD is a significant one as on October 18 1987, 50149 “Defiance” undertook its first main line trials to be evaluated if the 50/1 Railfreight project was worth pursuing.

These were not its first main line runs in its new two tone grey garb with yellow nameplates, but the official first tests under the scrutiny of the Railfreight sector to see if the concept was a good one. 

And to recall this day, I turn to Ian Horner’s notes, in turn generated from David Clough’s assessment of the day.

The much anticipated freight trials took place on Sunday October 18 on the gradient between Westbury and Warminster. This section was ‘under possession’ - closed to normal traffic, which meant that the ‘50/1’ could be stopped on the incline to attempt various restarts without disrupting normal service trains.

On a showery day the trials comprised of three runs at Warminster bank - with its gradient of around 1-in-70, hauling varying loads on the incline in conditions designed to test the locomotive’s ability to pull a load and just as importantly, keep its feet.

The aim of the conversion was to produce a locomotive that could match the hauling capability of a pair of Class 33s, which called for tractive-effort similar to that of a Class 56. No standard ‘50’ could be expected to produce that but by re-gearing its bogies and derating the power unit, it was reckoned that 50149 would be able to deliver more power at lower speeds without overloading the electrical machinery.

The danger however, was that reduced power output would leave insufficient capability to keep the load going once the electronics had got it on the move. The Chairman of the Class 50 Society, David Clough, witnessed the trials at first hand from 50149’s cab and reported on the day in the Fifty Forum, a flavour of which is reproduced below.

For the first run departing around 0945, 50149 was handed a load of 11 loaded PTA – bogie aggregate box wagons, weighing 1,122 tons which it took to milepost (MP) 111 on the gradient for the first restart. With the driver feeling his way in, a slight traction motor overload occurred but the train pulled away well enough before being brought to a controlled stand near MP 111¾.

Here the track continued to climb through reverse curves and restarting here imposed a more difficult task but again, 50149 did well and quickly achieved 12mph with 2,000 amps. Rain was falling when the third restart – at MP 112½ was attempted meaning the planned simulation of poor railhead conditions was not called for.

As expected, in view of how things had gone so far, “Defiance” succeeded in its task quite easily. Another benefit of working in a possession was that a quick return to Westbury was facilitated by sending a Class 56 behind the train to attach and work back ‘wrong-line’.

At Westbury three PGA four-wheeled bottom-discharged wagons were added to the train to produce a new trailing weight of 1,275 tons for the second run. Prospects did not look good as 50149’s engine shutdown even before reaching the first restart. The locomotive was soon running again but suffered a traction motor overload just above MP 111, at only 2,200 amps.

Mr Clough noted that Driver Bevan of Westbury seemed happy to permit limited slipping but was careful to avoid high currents, helping to avoid wheelslip by throttling back when current reached 2,400 amps to around 1,800 amps - the usual maximum continuous current for a standard Class 50/0.

When slipping persisted, 50149’s control system wound the power off then reapplied it and gave the driver highly effective control on a difficult railhead. The restart in the reverse curves proved difficult with the heavier load however, and the train slipped to a stand near MP 111½.

After the rails had been sanded manually, “Defiance” made a clean restart but once clear of the sanded section, slipping reoccurred and the train ground to another halt. It seemed that oil dropped on the rails by the ‘56’ when it hauled the train back to Westbury earlier had made the 50149’s job a little more arduous than it should have been!

For the final run, a load of 1,122 tons (22 PGAs) was picked up and the ‘50/1’ initially made a clean getaway but on the restart from MP 111¾ in wet weather, a traction motor overloaded at around 2,000 amps. Another restart was made with some slipping but the engine shut down at around 3mph and the train came to another halt.

After more sanding, slipping and another traction motor overload the train limped on to milepost 112½ for the final restart. Perhaps surprisingly in view of the problems just experienced, “Defiance” positively shot-off up the bank and easily reached the summit where it was stopped to await a tow back to Westbury, where it arrived around 1515.

Mr Clough concluded that 50149 had done what it had been asked to do – lift 1,275 tons away from rest on the 1-in-70 incline, but this could only be managed in good rail conditions. On curved gradients and where the railhead was slippery the ‘50/1’ struggled for adhesion and could not restart its load without sanding the rails – after which no more problems were encountered.

Sanding capability had been removed from the 50s during refurbishment and it seemed this was sufficient to deem the class unsuitable for heavy freight work in the future without incurring the costs of reinstatement.

As the staff from the Railway Technical Centre at Derby and BR (WR) at Swindon left to contemplate what they’d learned, Mr Clough paid tribute to the basic merits of the ‘first generation’ electronics in the Class 50 power and control circuitry which put the locomotives ahead of their time when introduced. Two decades on the systems were proved still capable of delivering the goods.

After its freight trials 50149 visited Cardiff Canton depot before being used on general freight work in the Westbury and Exeter Riverside areas. It took a train of empty ballast wagons to Meldon Quarry on October 21 and largely remained on Departmental duties to the end of the month.

Over the next few months 50149 worked various freight trains, but in November 1987, a collision between two of Laira’s China Clay 37s, 37670/671, saw the loco outbased at St Blazey depot in Cornwall as cover for one of the 37s.

It spent most of 1988 on these duties, although did work to Gloucester and Tavistock Junction Yard on various freight trains, plus the odd other non-freight job on vans, ECS or even the occasional passenger train (a subject for a later OTD).

In February 1989 the loco returned to Laira and was returned to its original number as 50049, repainted into NSE livery and added to the NSSA pool for Exeter St David's-Waterloo work.

And of course, as we all know the loco survives today, and is back in a freight livery…. GB Railfreight livery that is!

Edited October 18, 2019 by mevaman1
Mid type

[GordonC]

Thats fascinating that it was rejected for heavy freight work based on the lack of sanding equipment following refurbishment. Would it have been all that expensive to reinstate?

 

[royaloak]

1 hour ago, GordonC said:

Thats fascinating that it was rejected for heavy freight work based on the lack of sanding equipment following refurbishment. Would it have been all that expensive to reinstate?

 

No, because it was all still in place (at least on 50017), they simply welded a plate over the sandbox fillers leaving everything (including the lids) in place, I am not sure about the later refurbishments.

Edited October 18, 2019 by royaloak
to add loco number

[royaloak]

8 hours ago, GordonC said:

 

Railfreight General sector - only a handful of locos ever received it. Only 50149 and 50117 (once in preservation) carried it

I believe 50149 was the only one to carry the livery while in mainline use, 50117 carried it in preservation only.

[NIRCLASS80]

I believe the price to reinstate it was quoted in some press article at the time to be around £7000 per locomotive. 

[Welsh Signaller]

23 hours ago, GordonC said:

 

Railfreight General sector - only a handful of locos ever received it. Only 50149 and 50117 (once in preservation) carried it

37114, 50149, 60010, 87101 maybe a 86 as well I’m not sure.

[hmrspaul]

One of my photos of 50149 on 29/10/87 https://PaulBartlett.zenfolio.com/class50/ebe0ea96e

 

Paul

[YesTor]

86602  https://www.flickr.com/photos/50619197@N07/27118427836/

 

[GordonC]

On 19/10/2019 at 08:54, Welsh Signaller said:

37114, 50149, 60010, 87101 maybe a 86 as well I’m not sure.

 

there was a thread about it which I cant find just now. There was also 37403, 37673 and several 86s if I remember right 86502, 86602, 86627, some were in service and some only carried it on one side temporarily for publicity purposes. The symbol also appeared on other locos without necessarily the full livery like a couple of class 08s

 

 

[Accurascale Fran]

On 27/06/2019 at 22:11, lyneux said:

Hi Gents. Please can you confirm the coupling style for the inner wagons?

 

The coupling should be centred through the fretwork as per below:

 

 

I note from the CADs that this would appear not to be the case although the artwork shows the couplings at the correct height. I'm confused?

 

Guy

 

 

Hi everyone,

 

You may remember we had a bit of a debate around having the knuckle coupling for the inner wagons at prototypical or NEM height. As you may remember, we decided in the end to try the prototypical height for the inner wagons (and NEM standard for the outer wagons with buffers) and can now show you how that looks after successful testing! 

 

 

Outer wagons (which will couple up to your loco/other wagons below!

 

 

The arrangement has produced a bit of a unique knuckle coupling arrangement (with NEM socket) and performs very well around tight curves. We're very happy with it.

 

Cheers!

 

Fran

 

 

[Mark Saunders]

Fran

 

I have never understood the logic of inners at with the couplings at any other height than those of the the real thing, outer with drawbar hooks and screw couplings are open to personal preference!

 

Mark

[Accurascale Fran]

1 hour ago, Mark Saunders said:

Fran

 

I have never understood the logic of inners at with the couplings at any other height than those of the the real thing, outer with drawbar hooks and screw couplings are open to personal preference!

 

Mark

 

Hi Mark,

 

There was two reasons behind it initially;

 

1. A customer will just buy an inner pack and call us every single name under the sun as the coupling mounts are much higher than all their other stock. (This will happen, not everyone is a wagon expert or passionate enthusiast at the end of the day and they just want to ‘play trains’)

 

2. We had some small reservations about performance with a coupling higher than the weight, centrifugal forces etc which we are delighted to report have been unfounded with testing. At the end of the day we have to test our stuff in ‘train set’ conditions as well as consider more serious modellers.

 

Hope that clears up the initial thinking behind it.

 

Cheers!

 

Fran

[mevaman1]

Hi Fran

 

Our (Redruth MRC) experience of running freight-focussed OO layouts is that uncoupling/derailing with bogie wagons generally happens between loco and stock.  Stock/locos with couplings mounted on the bogies (Bachmann locos/stock, for instance) rarely cause problems.  However stock/locos with chassis mounted couplings (some Hornby and Dapol locos/stock, for instance)  often derail, particularly when propelling over complex pointwork.

 

The problems generally stem from couplings not recentering and we apply silicon grease to the coupling cams to ease this.

 

We have Dapol MJAs fitted with Kadees between the twin sets of wagons and this seems to work.  So, the use of knuckler couplings fitted to inners, I think, is a good idea.

 

The outer couplings may be more of a problem if fitted to the chassis.  I can’t tell from the photo if this is the case and would value your confirmation.

 

If possible, I would test the stock with a Hornby 60 propelling over a fan of pointwork!  
 

Hope that this helps and that I am not coming across as a ‘knowitall’.

 

Andrew

Edited November 7, 2019 by mevaman1
Spelling correction

[dj_crisp]

Looks smashing and the prototype height couplings look so much better than NEM height. They're exactly the arrangment i do for my inner coaching stock when i remount the kadee onto the body of the coach. It works well and having no buffers on the PTA I expect will allow them to go round pretty tight curves. I tend to snip off the auto bar thing as I don't shunt them so will do the same for PTAs

[Accurascale Fran]

4 hours ago, mevaman1 said:

Hi Fran

 

Our (Redruth MRC) experience of running freight-focussed OO layouts is that uncoupling/derailing with bogie wagons generally happens between loco and stock.  Stock/locos with couplings mounted on the bogies (Bachmann locos/stock, for instance) rarely cause problems.  However stock/locos with chassis mounted couplings (some Hornby and Dapol locos/stock, for instance)  often derail, particularly when propelling over complex pointwork.

 

The problems generally stem from couplings not recentering and we apply silicon grease to the coupling cams to ease this.

 

We have Dapol MJAs fitted with Kadees between the twin sets of wagons and this seems to work.  So, the use of knuckler couplings fitted to inners, I think, is a good idea.

 

The outer couplings may be more of a problem if fitted to the chassis.  I can’t tell from the photo if this is the case and would value your confirmation.

 

If possible, I would test the stock with a Hornby 60 propelling over a fan of pointwork!  
 

Hope that this helps and that I am not coming across as a ‘knowitall’.

 

Andrew

 

Hi Andrew,

 

These are body mounted with cam, as the NEM pockets are not required on the inner wagons, it would've been a big cost to tool two different bogies with bogie mounted NEMs. They have been tested and performed well on nice and uneven track, I'm sure they will do well on your layout too! One of the big battles is having the NEMs at correct height, which these do, and tension locks are poor for pushing as we all know, but at least they can be easily swapped out if desired. 

 

Cheers!

 

Fran

[SouthernMafia]

23 hours ago, Accurascale Fran said:

 

Hi Andrew,

 

These are body mounted with cam, as the NEM pockets are not required on the inner wagons, it would've been a big cost to tool two different bogies with bogie mounted NEMs. They have been tested and performed well on nice and uneven track, I'm sure they will do well on your layout too! One of the big battles is having the NEMs at correct height, which these do, and tension locks are poor for pushing as we all know, but at least they can be easily swapped out if desired. 

 

Cheers!

 

Fran

 

Agree, every modeller should have a length of track with a NEM/Kadee coupling jig to ensure all stock is at the same height.

 

Great to see opinion from us lot was taken on board and modifications made to the model. These can't be far off now?

[Accurascale Fran]

1 hour ago, SouthernMafia said:

 

Agree, every modeller should have a length of track with a NEM/Kadee coupling jig to ensure all stock is at the same height.

 

Great to see opinion from us lot was taken on board and modifications made to the model. These can't be far off now?

 

Still on course for January Rich, just a couple of small corrections are required! 

 

Cheers!

 

Fran

[lyneux]

They're looking great Fran! Have you got a shot 'end-on' of the inners please? The auto air brake force adjustment equipment (or whatever it's called - the thing on the bogie by the ladder) looks nice and fine too. Any chance of a 'closer look' at this too?

 

Thanks,

 

Guy

[Accurascale Fran]

1 hour ago, lyneux said:

They're looking great Fran! Have you got a shot 'end-on' of the inners please? The auto air brake force adjustment equipment (or whatever it's called - the thing on the bogie by the ladder) looks nice and fine too. Any chance of a 'closer look' at this too?

 

Thanks,

 

Guy

Hi Guy,

 

Sure, will have to wait till Monday though I’m afraid!

 

Cheers!

 

Fran

[Steadfast]

2 hours ago, lyneux said:

They're looking great Fran! Have you got a shot 'end-on' of the inners please? The auto air brake force adjustment equipment (or whatever it's called - the thing on the bogie by the ladder) looks nice and fine too. Any chance of a 'closer look' at this too?

 

Thanks,

 

Guy

Guy, it's called the variable load valve. A set of these on Whatley will be a sight to behold!

Agreed, the Accurascale guys have done a lovely job on the detail, almost enough to tempt me up a scale!

 

Jo

[bazjones1711]

for those who wish to run  a short train of ore wagons

 

[Mark Saunders]

4 minutes ago, bazjones1711 said:

for those who wish to run  a short train of ore wagons

 

 

The Ravenscraig ones ran shorter formations when in Dolofines out of Thrislington!

 

The load up to Consett from Redcar was a pair of 37's and 9 PTA's.

 

Mark Saunders

Edited November 13, 2019 by Mark Saunders
Consett