Why were 86/1s & 86/2s not the other way around?

[Pete the Elaner]

adding into the mix, over the years there were Class 86/0, 86/1, 86/2, 86/3, 86/4, 86/5, 86/6, 86/7, 86/9

I know.. & 86/5 was used twice. The first time for modified 86/2s, but they all got recalled by I/C & re-instated as 86/2s. It got used a 2nd time for a 1-off conversion. I am not sure but this one may still be in service.

I don't know how 86/7 & 86/9 differed but I believe there were only 2 of each & I don't think any of these 4 are still running in the UK.

[Pete the Elaner]

From the AC Loco Group pages again....

 

The first significant change to the Class 86 fleet (as it became known in the early 70s) was the separation of the class into two principle sub classes, determined by the traction motor type. The 86/0s were the standard loco, essentially as built, and were generally restricted to freight and slower passenger duties, with their maximum speed dropped from 100mph to 80mph. The 86/2s became the high-speed passenger locomotives, all being fitted with flexicoil suspension. Forty-nine locomotives were originally converted, increased soon afterwards to 58. As traction motor types were distributed amongst the fleet seemingly at random, renumbering from the original E3XXX series to the new TOPS series was also essentially random, so, for instance, 86001 was not previously E3101.

Seen that site many times but not digested that bit. I guess that fitting of flexicoils followed what traction motors were fitted then?

['CHARD]

Seen that site many times but not digested that bit. I guess that fitting of flexicoils followed what traction motors were fitted then?

 

Reckon so.  

 

Now, for my next trick, I'll see if there was any batch consistency to which the two types of motor were fitted....

['CHARD]

'Express passenger' motors (my designation) were fitted to:

 

3101/ 6/ 7/ 13/ 6-9/ 21/ 5-7/ 9/ 31-44/ 7/ 9-51/ 4-6/ 8/ 61/ 2/ 4-9/ 72/ 3/ 5/ 7-9/ 81-4/ 9-94/ 6/ 7.

 

By elimination, the 'mixed traffic' machines were:

 

3102-5/ 8-12/ 4/ 5/ 20/ 2-4/ 8/ 30/ 45/ 6/ 8/ 52/ 3/ 7/ 9/ 60/ 3/ 70/ 1/ 4/ 6/ 80/ 5-8/ 95/ 8-100.

 

I don't see any pattern there.  Note also that some 86/0 were later renumbered to 86/2 (the last ten, 253-262), i.e. a few years after TOPS had come in.  This suggests that they had their traction motors re-rated at the same time.

 

 

(EDITED for missing 86/2s)

Edited July 18, 2017 by 'CHARD

[rodent279]

Is there a pattern amongst builders? Were all those that eventually became 86/0, 3, 4 or 6, built at Doncaster, and all those that became 86/2's built at VF? Or was it entirely random?

[Pete the Elaner]

I agree, that looks very random.

It makes you wonder how difficult is was to select the right loco in the days before TOPS sub-classes.

[298]

Be careful, the underframe gear changed at some point late in life and what is under the preserved one is not as it was when she was first converted.

 

Andi

Is that just the fire suppression equipment (Halon to Inergen), or additional bits too? I'll have to check my photos.

 

The box in question on the /1s houses the weak field equipment for the traction motors on the BP9 bogies.

[298]

I agree, that looks very random.

It makes you wonder how difficult is was to select the right loco in the days before TOPS sub-classes.

.

 

That's the problem with applying 2017 logic to 1970s thinking, especially when BR didn't seem to have a uniform renumbering pattern, but at least they weren't bothered about two vehicles clashing, such as a Deltic and a Bubble car.

Edited July 18, 2017 by 298

['CHARD]

Is there a pattern amongst builders? Were all those that eventually became 86/0, 3, 4 or 6, built at Doncaster, and all those that became 86/2's built at VF? Or was it entirely random?

 

3101-40 Doncaster

 

3141-200 EE/ VF

Edited July 18, 2017 by 'CHARD

[Peter Kazmierczak]

BR Doncaster were originally to build E3101 - E3160 and EE Vulcan Foundry E3161 - E3200.

 

This was subsequently changed to BR building E3101 - E3140 and EE E3141- E3200.

 

E3101 - E3110 Doncaster EO20 (1965)

E3111 - E3120 Doncaster EO24 (1965)

E3121 - E3130 Doncaster EO25 (1965)

E3131 - E3140 Doncaster EO26 (1965-66)

 

E3161 - E3179 Vulcan Foundry order 6420 (1965)

E3180 - E3200 Vulcan Foundry order 6421 (1965-66)

 

E3141 - E3160 Vulcan Foundry order 6673 (1966)

[cheesysmith]

If you look at the different traction motors, the bz motor has a higher HP but also a different toque peak, meaning it has different gearing and also (a guess here) different weak field. I remember reading that for the AC locos there was a use of minimum weak fields. As for the numbering, the only reason I can see was to avoid TOPS number used for BG NPCCCs.

 

With more practice with TOPS as time passed, this problem was realised to not exist.

[stovepipe]

I think the fact that BR ended up with 40 80mph and (approx) 60 100mph locomotives is significant, given the split between builders. The David & Charles AC Loco of BR Book, say the motors were interchangeble, so the ones selected for the 86/2 treatment weren't necessarily the ones intially fitted with the 282BZ motors.

[keefer]

IIRC the clash between loco and LHCS numbers didn't really matter until the early '80s, when the coaches & DMU/EMU vehicles went onto TOPS.

Until then, the regional prefix was part of the coach number and that differentiated them from locos with the same digits.

But because the computer system couldn't use the prefix, then stock had to be renumbered so that only one vehicle of any type had a certain number.

[rodent279]

If you look at the different traction motors, the bz motor has a higher HP but also a different toque peak, meaning it has different gearing and also (a guess here) different weak field. I remember reading that for the AC locos there was a use of minimum weak fields. As for the numbering, the only reason I can see was to avoid TOPS number used for BG NPCCCs.

 

With more practice with TOPS as time passed, this problem was realised to not exist.

 

I believe that class 86's were designed to work over their full torque/speed range without field weakening.

[cheesysmith]

Reading through AC electric locos of British rail by webb and Duncan it does say that at the time BR was trying to solve the ride problems of these locos, whIch was the tome TOPs was being introduced, the class was going through Crewe works for bogie frame fractures, and analisyst of the bogies was putting a 6 month life of the bogies with the old design with the increased high speed miles that were going to be run when the wires were extended northward. BR had just spent £150 thousand repairing the cracks and re welding. I wonder if the numbering was that BR was considering putting the 87bogies under more of the locos if the SAB wheels and flexicoils didn't work.

 

Ps-the 86s only have a single stage of field weakening and identical gearing for both motors.

[rodent279]

Reading through AC electric locos of British rail by webb and Duncan it does say that at the time BR was trying to solve the ride problems of these locos, whIch was the tome TOPs was being introduced, the class was going through Crewe works for bogie frame fractures, and analisyst of the bogies was putting a 6 month life of the bogies with the old design with the increased high speed miles that were going to be run when the wires were extended northward. BR had just spent £150 thousand repairing the cracks and re welding. I wonder if the numbering was that BR was considering putting the 87bogies under more of the locos if the SAB wheels and flexicoils didn't work.

 

Ps-the 86s only have a single stage of field weakening and identical gearing for both motors.

 

Yep, you're right. I think there are two stages in the 81-85's.

 

Another anecdote from my dad, who was heavily involved with the electrification south to Euston. At one stage they were going through brushes for class 86's so quickly, he was having the manufacturers deliver them directly to his office! They had to change the spec of the brushes to a harder compound, they were just disintegrating. He was either at Euston or Bletchley at the time. He says there were proposals to mount a camera inside a motor to record what was going on. Someone did some tests and found that the motors were experiencing accelerations in the order of 100G, which was way more than any camera of the day could withstand.

Edited July 18, 2017 by rodent279

[DY444]

The motor design was changed part way through the build so those built first received 282AZ and those built later received 282BZ.  As locomotives were overhauled they didn't usually come out of the works with the same set of motors they went in with so over time the AZ and BZ motors got distributed randomly amongst the class (although a locomotive always had a set of 4 the same).  When the flexicoil programme started those that had BZ motors at the time were selected for fitment. 

 

Class 86 did not have field weakening.  Classes 81-5 and 87 did.

['CHARD]

The motor design was changed part way through the build so those built first received 282AZ and those built later received 282BZ.  As locomotives were overhauled they didn't usually come out of the works with the same set of motors they went in with so over time the AZ and BZ motors got distributed randomly amongst the class (although a locomotive always had a set of 4 the same).  When the flexicoil programme started those that had BZ motors at the time were selected for fitment. 

 

Class 86 did not have field weakening.  Classes 81-5 and 87 did.

 

There you are then - that's the second part of the explanation nailed.  Excellent contribution, sir!

[rodent279]

Class 86 did not have field weakening. Classes 81-5 and 87 did.

I thought so!

[rodent279]

Going back to numbers, and avoiding clashes, I've always wondered why BR didn't adopt a similar approach to DB, use 6 digit numbers, and number all electric locos starting with 1, diesels with 2, EMU's with 3, DMU's with 4, passenger coaches with 5 etc etc.

[Titan]

Going back to numbers, and avoiding clashes, I've always wondered why BR didn't adopt a similar approach to DB, use 6 digit numbers, and number all electric locos starting with 1, diesels with 2, EMU's with 3, DMU's with 4, passenger coaches with 5 etc etc.

 

I thought that was pretty much what they did under tops?

 

01-69 diesel locos - generally the higher the number the higher the power

70-79 DC Electric locos and Electro diesels

80-99 AC/dual voltage Electric locos

100-199 DMU

200-299 DEMU

300-399 AC/dual voltage EMU

400- 599? DC EMU

 

Of course it has gone to pot a bit recently...

[rodent279]

No. Effectively all locos are prefixed with 0, though it isn't in the number. So all locos, both diesel and electric, are in the range 000-099.

[slilley]

Originally there was just the Class 86. Two types of AEI traction motor were used one giving a rating of 3600hp, which were fitted to the locomotives built by English Electric, the second fitted to the Doncaster built examples had a rating of 4040hp.

 

Following the successful trials with E3173 with flexicoil suspension and SAB resilient wheels, it was decided that all the 4040hp locomotives would be modified in the same way.

 

In the early 1970s as part of the work on the Class 87s, locomotives 86201, 202, and 203 were fitted with Class 87 style bogies and traction motors. These became in turn 86101-86103.