Did yellow cab stripe on steam locos mean forbidden under the wires south of Crewe or under all wires?

[Trog]

One of my ex-colleagues was involved with tests involving lowering a 25Kv conductor wire until it set an arc to a steam engine funnel. So they could determine what clearances were needed. He also discovered that it was 'safe' or at least he did not end up a little bit dead, to stand with one foot on the footplate and one on the platform they were doing the testing in, while there was an arc in progress from the contact wire to the loco funnel. 

[Tom Burnham]

I believe the only areas where 6.25kV was used in regular service were Glasgow and the GE lines out of Liverpool Street. I think the Shenfield 1500V DC electrification was initially converted to 6.25kV using the original insulators and then gradually upgraded.  It was certainly possible to tell whether you were in 6.25kV or 25kV territory by looking at the number of discs on the insulators.

Was there an experimental section of 6.25kV on the Styal line which was used as a testbed for AC electrification?

[keefer]

Courtesy of Iain Logan's 'Electric Soup' website, here is a 1960 diagram showing the Voltages and changeover points on the Glasgow North (Helensburgh-Airdrie) electric system:

http://homepages.enterprise.net/iainlogan/railway/gsetk.html

Edited May 21, 2022 by keefer

[icn]

13 hours ago, rodent279 said:

I've read somewhere that it wasn't strictly necessary due to the higher currents on the 1500 v D.C. system (typically 1000A), it was more to even out pan head wear. Single pans are the norm in Holland, and on the 1500V D.C. lines of SNCF. NS & SNCF electric locos are considerably more powerful than either class of Woodhead loco, peak current draw from their ohl would easily be north of 3000A.

Can't speak to Holland, but in Poland with 3kV DC they do have special rules about using both pantographs in some situations - at least with older stock or heavier trains they'll generally put both up when stopped and moving off - precisely because of the currents.. (Newer equipment can likely limit currents via software at lower speeds so it's perhaps less common now?)

 

The photos that I've looked at suggest that Dutch OHLE actually consists of 2 wires - could that be the difference? (I did also find one video of a Dutch loco following the Polish practice, but I figure that's not common?)

[lanchester]

5 hours ago, Tom Burnham said:

I believe the only areas where 6.25kV was used in regular service were Glasgow and the GE lines out of Liverpool Street. I think the Shenfield 1500V DC electrification was initially converted to 6.25kV using the original insulators and then gradually upgraded.  It was certainly possible to tell whether you were in 6.25kV or 25kV territory by looking at the number of discs on the insulators.

Was there an experimental section of 6.25kV on the Styal line which was used as a testbed for AC electrification?

I had always been under the impression that the Styal line electrification had been at 6.25kV initially, but confess I can't find any evidence for that. An urban myth?

 

But there may have been a lot of 'urban myth' even in the day, 28 July 1968, Dad and I were on a railtour, promoted by the Severn Valley and Manchester Rail Travel Societies ,originating and terminating  BNS, around Lancashire, the last steam-hauled segment of which was with 48773 from Rose Grove: and all the 'pre flight info' said that would come off at Man Vic (from memory I think the wires issue may even have been mentioned in the literature - my timing sheet is currently in storage with the rest of my previous life, so I can't check). Nonetheless, 48773 went on via Droylsden to finish under the wires at Stockport (where we were picked up by the same Brush 4, (D1945 from memory although I may be wrong on the last digit) as had brought us up that morning. Point is, Everyone (not just spotty eleven year olds like me) on the train was amazed - this isn't allowed, look at the yellow stripe. So the belief that yellow stripe was a total ban under the 25kV wires was, I think, universal - regardless of what the actual rules may have been.

 

Note this info does not totally correspond with what is on Six Bells Junction (including the ID of the Brush 4). When I finally get my stuff out of storage, if its still there - not checked for about four years but I'm still paying the fees, and now that the Mother in Law has 'passed' (side query- why does everyone now 'pass': why don't they just die, like people used to?) and we can get our own stuff into the house I will find the timing sheet, confirm and email the Six Bells chappy accordingly. But 48773 under the wires at Stockport is definitely true..

[woodenhead]

5 minutes ago, lanchester said:

I had always been under the impression that the Styal line electrification had been at 6.25kV initially, but confess I can't find any evidence for that. An urban myth?

 

The Styal line was one of the two pilot lines for 25Kv and the first AC electric was 25Kv so it would be odd that they would have chosen 6.25kv for the initial wiring and then upgraded it ready for full implementation.

[Tom Burnham]

According to "The History of the Electric Locomotive" by F J G Haut (1969) the original AC electric locos (classes AL1 to AL5, 81 to 85) were designed to transition from 6.25kV to 25kV and vice versa at neutral sections.  The AL6 (class 86) locos were designed for 25kV only.

[jim.snowdon]

15 hours ago, Tom Burnham said:

I believe the only areas where 6.25kV was used in regular service were Glasgow and the GE lines out of Liverpool Street. I think the Shenfield 1500V DC electrification was initially converted to 6.25kV using the original insulators and then gradually upgraded.  It was certainly possible to tell whether you were in 6.25kV or 25kV territory by looking at the number of discs on the insulators.

Was there an experimental section of 6.25kV on the Styal line which was used as a testbed for AC electrification?

One of the papers presented at the 1960 BR Electrification Conference contains a table giving the route mileages of 25kV and 6.25kV electrification, both completed  and under construction. Crewe to Euston is shown as having 48 route miles of 6.25kV, although given the date, I would presume that this was a planned figure that may have reduced to zero by the time the relevant sections were actually energised. There is zero route mileage listed for the Manchester - Crewe and Liverpool - Crewe sections.

 

[6990WitherslackHall]

From what I know, they were forbidden from working under the wires south of Crewe. 

[DY444]

On 21/05/2022 at 09:12, Tom Burnham said:

Was there an experimental section of 6.25kV on the Styal line which was used as a testbed for AC electrification?

 

On 21/05/2022 at 15:14, lanchester said:

I had always been under the impression that the Styal line electrification had been at 6.25kV initially, but confess I can't find any evidence for that. An urban myth?

 

Styal was 25kV only. 

 

Colchester-Clacton/Walton was fitted with two temporary neutral sections close together near Alresford.  The short section between them could be configured as either 25kV or 6.25kV and was used for basic functional testing of the changeover mechanism on trains as required.  When specific changeover testing was not in progress the section was left configured at 25kV.

Edited July 20, 2022 by DY444

[Tom Burnham]

Thanks, DY444!

[Titan]

I think the LTS line from Fenchurch Street had sections of 6.25kV too.

[Mallard60022]

Duchess is/was speed restricted just north of Botany Bay Xing, if accelerating North, at an overbridge, presumably due to brief lowering of the wires in just that position? May have just been on one trip I witnessed due to track alignment/height after engineering?

P

[Clive Mortimore]

As far as I am aware the standard contact wire height for both 1500v DC and Mk1 25KV AC was 16ft 6ins. I have not read anything about a higher contact wire on the sections to Manchester and Liverpool from Crewe.

 

The 6.25KV AC as used on the GER and LTSR lines out of London was mainly due keeping cost down as the 1500V DC insulators were capable of handling 6.25 KV AC, from the 1960 Electrification Conference papers. Why the London end of the CHENFORD scheme was 6.25KV with 25KV insulators when built I don't know.  And why the Shenfield to Chelmsford  section of the old 1500v DC was converted to 25KV AC early on again is a mystery.

 

As to the yellow stripe, it was mainly confined to express classes. If you are trying to sell to the public a new modern railway between four of the major cities of England the last thing you want rocking up is a dirty puffing billy.

 

No idea why the super Ds got the stripe. The MR class 4 Superheated Goods were in use around Crewe works as shunters, I am sure it was to deter the crews from taking them outside the works. 

Edited July 20, 2022 by Clive Mortimore
To correct the normal contact wire height.

[6990WitherslackHall]

I know Jubilees, Princess Coronation 4-6-2s and 8Fs had them.

[LMS2968]

Only one 8F, 8773. I think I explained the story earlier in the thread.

[Steamport Southport]

3 hours ago, Clive Mortimore said:

As far as I am aware the standard contact wire height for both 1500v DC and Mk1 25KV AC was 16ft. I have not read anything about a higher contact wire on the sections to Manchester and Liverpool from Crewe.

 

The 6.25KV AC as used on the GER and LTSR lines out of London was mainly due keeping cost down as the 1500V DC insulators were capable of handling 6.25 KV AC, from the 1960 Electrification Conference papers. Why the London end of the CHENFORD scheme was 6.25KV with 25KV insulators when built I don't know.  And why the Shenfield to Chelmsford  section of the old 1500v DC was converted to 25KV AC early on again is a mystery.

 

As to the yellow stripe, it was mainly confined to express classes. If you are trying to sell to the public a new modern railway between four of the major cities of England the last thing you want rocking up is a dirty puffing billy.

 

No idea why the super Ds got the stripe. The MR class 4 Superheated Goods were in use around Crewe works as shunters, I am sure it was to deter the crews from taking them outside the works. 

 

Yet there was still 8677 ordinary steam locomotives in 1963 when the yellow stripe appeared. 7050 made it into 1964. Many of which worked quite regularly south of Crewe.

 

That included ancient M7s at Waterloo which were replaced by Pannier Tanks!

 

Willesden still had a steam allocation until 1965.

 

 

It had nothing to do with them being steam locomotives, it was because certain ones were now out of gauge. Which is why the G2s and 4Fs also go them.

 

 

Jason

[Clive Mortimore]

1 hour ago, Steamport Southport said:

 

 

It had nothing to do with them being steam locomotives, it was because certain ones were now out of gauge. Which is why the G2s and 4Fs also go them.

 

 

Jason

Oh dear cynicism doesn't seem to work in some parts.

 

Sorry dimensions are for 4mm modellers

 

 

 

[Clive Mortimore]

There has been talk about 6.25Kv ac to 25Kv ac, here are my drawings of the neutral section between the 6.25Kv and 25 Kv on the Up Line on the southern end of the Southbury Loop. There was a similar five portal neutral section on the northern end for the down line.

 

[Poor Old Bruce]

On 20/07/2022 at 11:26, Clive Mortimore said:

As far as I am aware the standard contact wire height for both 1500v DC and Mk1 25KV AC was 16ft 6ins. I have not read anything about a higher contact wire on the sections to Manchester and Liverpool from Crewe.

 

16ft 6in would be the 'nominal' contact wire height on open track. Remember that the contact wire height was raised at level crossings and reduced at overbridges

 

On 20/07/2022 at 14:37, 6990WitherslackHall said:

I know Jubilees, Princess Coronation 4-6-2s and 8Fs had them.

 

The remaining A3s and A4s got the stripe as well. It was to do with the overall height of the loco.