Catenary between Chelmsford and Hatfield Peverel

[gobbler]

Just a general question really. Not expecting an answer. But if it could be answered I'd be really interested because I might want to try to do a small section.

 

Any way enough waffle.....

 

Q. Why are there so many types of catenary between Chelmsford and Hatfield Peverel?

 

Some of the types seen

 

1. 10inch approx single pole. These are opposite each other mainly, with alternating suspension arms

2. 10inch approx single pole but with two suspension arms on an H section.

3. Lattice type that fully goes over both tracks

4. Single side lattice that only holds wires for one side of the track

5. Single side lattice that holds wires for both sides

6. H section over both sides

7. Double H section

 

There are other types which hold the supply to the over heads and others for tensioning.

Others that look like they do nothing.

 

There seems to be no logic or order in which they are placed except the ones over the small viaduct in Boreham and Hatfield Peverel . Are they just experiments??

 

Would love to know weather there is a survey done on this section.

 

Cheers in advance

 

Scott

[russ p]

I've often wondered that I think it was probably a case of different designs being tried out as it was a very early mainline recipient of 25kv electrification

[TravisM]

Just a general question really. Not expecting an answer. But if it could be answered I'd be really interested because I might want to try to do a small section.

 

Any way enough waffle.....

 

Q. Why are there so many types of catenary between Chelmsford and Hatfield Peverel?

 

Some of the types seen

 

1. 10inch approx single pole. These are opposite each other mainly, with alternating suspension arms

2. 10inch approx single pole but with two suspension arms on an H section.

3. Lattice type that fully goes over both tracks

4. Single side lattice that only holds wires for one side of the track

5. Single side lattice that holds wires for both sides

6. H section over both sides

7. Double H section

 

There are other types which hold the supply to the over heads and others for tensioning.

Others that look like they do nothing.

 

There seems to be no logic or order in which they are placed except the ones over the small viaduct in Boreham and Hatfield Peverel . Are they just experiments??

 

Would love to know weather there is a survey done on this section.

 

Cheers in advance

 

Scott

 

I believe that when the line was first electrified, it was originally 1500V DC as per the Woodhead route which I believe was going to be the standard at the time but as the French improved AC overhead in the 50's, it was decided to go with their system, so it was later converted.  Also after the conversion, parts of it were only 6.25 KV instead of 25 KV 

[Clive Mortimore]

Just a general question really. Not expecting an answer. But if it could be answered I'd be really interested because I might want to try to do a small section.

 

Any way enough waffle.....

 

Q. Why are there so many types of catenary between Chelmsford and Hatfield Peverel?

 

Some of the types seen

 

1. 10inch approx single pole. These are opposite each other mainly, with alternating suspension arms

2. 10inch approx single pole but with two suspension arms on an H section.

3. Lattice type that fully goes over both tracks

4. Single side lattice that only holds wires for one side of the track

5. Single side lattice that holds wires for both sides

6. H section over both sides

7. Double H section

 

There are other types which hold the supply to the over heads and others for tensioning.

Others that look like they do nothing.

 

There seems to be no logic or order in which they are placed except the ones over the small viaduct in Boreham and Hatfield Peverel . Are they just experiments??

 

Would love to know weather there is a survey done on this section.

 

Cheers in advance

 

Scott

 

 

From Abour Lane Bridge to Hatfield Peverel station it is a very logical system, and of one type, it is the same system from Chelmsford to Colchetser.

 

It is Mk1 25KV Ac system mounted on round uprights for cantilever mast. The bridge portals are made from welded round section rod of varying diameters. At Boreham where an addition power feed was added in the 90s there are a few mast that are not standard including H section uprights and double cantilevers (single lattice mast ) but that happens when things are improved or modified. Another example of modification is at Generals Lane  where it had been a level crossing with raised contact wire height, when the Boreham bypass was built a bridge replaced the crossing and you have tall mast with reduced system height cantilevers to bring the wires under the bridge.

 

Standard cantilever mast, at Boreham. 

 

Standard portal mast, this is a mid point anchor, Boreham.

 

The next set of photos are for a overlap at Boreham, thsi is where one wire run ends and another starts. 

This overlap differs from the others near by as the tensioning weights are on separate masts. The mast with two cantilevers carry one wire that is in contact with the pantograph and one that is not.

The portal in the middle is a booster transformer, the name is slightly misleading, they do not boost the power to the contact wire but help harmonise the return current with the power current. Stops your landline phone lines being effected by the magnetic fields generated or something like that.

 

Portal mast over where the New Hall siding was, lifted in the 1980s.

 

Mast with lower system height and contact wire height where a bridge use to be. These show the mast found either side of most bridges without the bridge being in the way. At the junction where the Hatfield Peverel turnoff the A12 starts.

 

H section mast at generals lane after the bridge was built and the level crossing removed.

 

This mast use to have two cantilevers on it, the other one was dismounted when the crossing on the Chlemsford end of Hatfield Peverel station was removed.

 

Each mast is an individual and has its own function to perform. 

[gobbler]

Cheers chaps

 

If anyone else has anything else to add, please do.

 

Scott

[Clive Mortimore]

I believe that when the line was first electrified, it was originally 1500V DC as per the Woodhead route which I believe was going to be the standard at the time but as the French improved AC overhead in the 50's, it was decided to go with their system, so it was later converted.  Also after the conversion, parts of it were only 6.25 KV instead of 25 KV 

That was the London side of Chelmsford.

[gobbler]

Wow, cheers Clive, well there you go.....,

 

More detail than you can shake a stick at.

 

Are they your pics?

It would take a brave man to walk along the A12 to take those pix, which is where most of them seem to be taken.

 

Cheers again Clive

 

Scott

 

P.S happy new year all

[Clive Mortimore]

Wow, cheers Clive, well there you go.....,

 

More detail than you can shake a stick at.

 

Are they your pics?

It would take a brave man to walk along the A12 to take those pix, which is where most of them seem to be taken.

 

Cheers again Clive

 

Scott

 

P.S happy new year all

Hi Scott

 

They are mine. I have some others, somewhere. I seem to have mislaid them in the move from Essex to here.

 

Not brave just strange to walk along the A12 taking photos. Mind you the traffic kept slowing down.

 

Yours

 

Spider

[gobbler]

Hi Scott

 

They are mine. I have some others, somewhere. I seem to have mislaid them in the move from Essex to here.

 

Not brave just strange to walk along the A12 taking photos. Mind you the traffic kept slowing down.

 

Yours

 

Spider

If you can have 'favourites' they would be the lattice ones that are 'planted' one side only and carry the wires for one track and the lattice that's planted on one side carrying wires for both sides. I've spotted only a couple of these on the 5-6 mile stretch.

 

P,s bet you got some strange looks. Surprised the police didn't turn up.

 

Ta again scott

[Pete the Elaner]

If you can have 'favourites' they would be the lattice ones that are 'planted' one side only and carry the wires for one track and the lattice that's planted on one side carrying wires for both sides. I've spotted only a couple of these on the 5-6 mile stretch.

There are a few of this type on the WCML just south of Watford Gap; the bit you can see in the distance from the M1. I believe they were put there early as part of the line's 125mph upgrade.

Edited January 2, 2018 by Pete the Elaner

[The Stationmaster]

If you can have 'favourites' they would be the lattice ones that are 'planted' one side only and carry the wires for one track and the lattice that's planted on one side carrying wires for both sides. I've spotted only a couple of these on the 5-6 mile stretch.

 

P,s bet you got some strange looks. Surprised the police didn't turn up.

 

Ta again scott

 

Quite a few of that style are going in on the GWML scheme although the lattice is  more substantial than earlier versions and they have a 'solid' upright instead of lattice.  You can see several in the right background in this pic (click on the picture to enlarge).

 

[iands]

If you can have 'favourites' they would be the lattice ones that are 'planted' one side only and carry the wires for one track and the lattice that's planted on one side carrying wires for both sides. I've spotted only a couple of these on the 5-6 mile stretch.

P,s bet you got some strange looks. Surprised the police didn't turn up.

Ta again scott

I think the technical term for these are "Single Track Cantilever" and "Twin Track Cantilever".

 

Regards, Ian.

[Clive Mortimore]

If you can have 'favourites' they would be the lattice ones that are 'planted' one side only and carry the wires for one track and the lattice that's planted on one side carrying wires for both sides. I've spotted only a couple of these on the 5-6 mile stretch.

 

P,s bet you got some strange looks. Surprised the police didn't turn up.

 

Ta again scott

 

I think the technical term for these are "Single Track Cantilever" and "Twin Track Cantilever".

 

Regards, Ian.

Hi Scott and Ian

 

There are only two twin track cantilevers that I can recall. Both to a similar design to Mk3 with Mk1 registration arms. They support the wires over the two crossovers put in place in the 1990s when the GER line was resignaled to allow bidirectional running on both lines during the morning and evening rush which has never been used.

 

Edit , if I find my other photos I have both mast in my collection. The mast carry two cantilevers over the point heals are also mk3 design with mk1 arms. When these were installed an additional power feed station was also built, that too has some hybrid mast, again the photos of this are somewhere. 

Edited January 2, 2018 by Clive Mortimore

[Dagworth]

Excellent thread with some great photos and information. Nice to see someone else taking an interest in the knitting. 

 

Just don't mention the overhead at Witham, Clive will have one of his "turns" again

 

Andi

[Clive Mortimore]

The power feed station at Boreham, dimensions for 4mm scale. 

 

 

[Clive Mortimore]

Excellent thread with some great photos and information. Nice to see someone else taking an interest in the knitting. 

 

Just don't mention the overhead at Witham, Clive will have one of his "turns" again

 

Andi

Witham, I can do Witham pre-bridge over Motts Lane and the new station entrance on the London bound side.

[Titan]

I think the technical term for these are "Single Track Cantilever" and "Twin Track Cantilever".

 

Regards, Ian.

 

 

Hi Scott and Ian

 

There are only two twin track cantilevers that I can recall. Both to a similar design to Mk3 with Mk1 registration arms. They support the wires over the two crossovers put in place in the 1990s when the GER line was resignaled to allow bidirectional running on both lines during the morning and evening rush which has never been used.

 

Edit , if I find my other photos I have both mast in my collection. The mast carry two cantilevers over the point heals are also mk3 design with mk1 arms. When these were installed an additional power feed station was also built, that too has some hybrid mast, again the photos of this are somewhere. 

 

 

Very slight mix up on terminology, but enough to cause confusion:

 

Two Track Cantilever, for supporting equipment over two tracks:

 

 

Twin Cantilever, for supporting two OLE equipments over one track, e.g. at crossovers and overlaps

 

 

Clive has probably got better examples to hand than me right now!

[iands]

Very slight mix up on terminology, but enough to cause confusion:

 

Two Track Cantilever, for supporting equipment over two tracks:

 

 

Twin Cantilever, for supporting two OLE equipments over one track, e.g. at crossovers and overlaps

 

 

Clive has probably got better examples to hand than me right now!

Hi Titan,

 

Many thanks for the clarification re the cantilevers.

 

Regards, Ian.

[wagonman]

The 1500V scheme only ventured as far as Shenfield. The Southend route was first electrified at 6,250V AC as it was thought the higher voltage being used in France wouldn't be safe under Essex bridges. The Great Panjandrums of BR later changed their minds and adopted 25kV AC as standard and the Southend (and other exGER lines) were converted. The 25kV had first been tried on the Colchester-Clacton lines. I'm not sure when they were linked to the main system but it was long before the final section to Norwich was electrified in the '80s.

[wagonman]

On the subject of OHLE, can anyone explain to me why the GWR main line electrification seems to be massively over-engineered. Or is this a can of worms best left shut?

[Titan]

The 1500V scheme only ventured as far as Shenfield. The Southend route was first electrified at 6,250V AC as it was thought the higher voltage being used in France wouldn't be safe under Essex bridges. The Great Panjandrums of BR later changed their minds and adopted 25kV AC as standard and the Southend (and other exGER lines) were converted. The 25kV had first been tried on the Colchester-Clacton lines. I'm not sure when they were linked to the main system but it was long before the final section to Norwich was electrified in the '80s.

 

Not true. the 1500VDC not only got as far as Southend, but reached Chelmsford too. 1500VDC Suburban stock was built for this, later being converted to Class 307 just a few years later.

 

There is a thread here on modelling the units as used on the Southend 1500VDC services:

 

http://www.rmweb.co.uk/community/index.php?/topic/126897-1956-er-1500v-dc-4-car-emu/

 

They ran from 1956.

 

The lines were then converted to 6.25kV AC as far as Shenfield, and 25kV AC from there onwards. I don't think Shenfield - Southend or Shenfield - Chelmsford were ever 6.25kV, going straight to 25kV  (Clive will probably know for sure)

 

BR did not change their minds, 25kV was the standard as soon as 1500VDC was dropped, and 6.25kV a compromise where the electrical clearances used in France could not be achieved. This was unreliable - and contributory to the exploding transformers on the class 303, as the automatic change over was a bit too automatic, So BR did its own experiments on electrical clearances, and found that you could get away with a lot less if you were careful. The 6.25kV was then converted to 25kV as soon as convenient.

 

The 'Gap' between Chelmsford and Colchester was filled in just in time for the 309's, pretty much at the same time as the conversion from 1500VDC of the rest of it.

Edited January 2, 2018 by Titan

[roythebus]

ISTR when my aunt moved to Chelmsford in 1960 it was electrified at 1500dc. Soon after they withdrew steam and brought in the Clacton electrics.

 

I think the change over to 6.25kv was around Seven Kings.

[Clive Mortimore]

Not true. the 1500VDC not only got as far as Southend, but reached Chelmsford too. 1500VDC Suburban stock was built for this, later being converted to Class 307 just a few years later.

 

There is a thread here on modelling the units as used on the Southend 1500VDC services:

 

http://www.rmweb.co.uk/community/index.php?/topic/126897-1956-er-1500v-dc-4-car-emu/

 

They ran from 1956.

 

The lines were then converted to 6.25kV AC as far as Shenfield, and 25kV AC from there onwards. I don't think Shenfield - Southend or Shenfield - Chelmsford were ever 6.25kV, going straight to 25kV  (Clive will probably know for sure)

 

BR did not change their minds, 25kV was the standard as soon as 1500VDC was dropped, and 6.25kV a compromise where the electrical clearances used in France could not be achieved. This was unreliable - and contributory to the exploding transformers on the class 303, as the automatic change over was a bit too automatic, So BR did its own experiments on electrical clearances, and found that you could get away with a lot less if you were careful. The 6.25kV was then converted to 25kV as soon as convenient.

 

The 'Gap' between Chelmsford and Colchester was filled in just in time for the 309's, pretty much at the same time as the conversion from 1500VDC of the rest of it.

Hi Ian

 

The Shenfield to Chelmsford section of 1500v Dc was the first converted to 25Kv Ac, never being 6.25Kv. Without digging out my books etc I cannot recall if the Southend line was done at the same time. The rest of the ex 1500v Dc section was at 6.25Kv Ac when first converted. I have just spent an hour skim reading a 500 page paper from the 1960 OLE conference hoping to find the paragraph that states the 1500V Dc insulators were suitable for 6.25 Kv Ac as I had mentioned on Brian's Southend stock thread. When I do I will send you a copy. I think because of the electrical supply the 6.25Kv Ac  was installed new to the line out towards Enfield, Chingford and Bishops Sortford. The change over point was on the Southbury loop. Photos indicate this section from Bethnal Green was built with 25 Kv Ac insulators. The usual reason for 6.25Kv Ac usage is the bridge clearance, I suspect the cost not only finical but also to the service on conversion was a consideration and the supply in the London area. 

Edited January 2, 2018 by Clive Mortimore

[298]

On the subject of OHLE, can anyone explain to me why the GWR main line electrification seems to be massively over-engineered. Or is this a can of worms best left shut?

Basically to stop the weekly de-wirements as seen on the ECML.

 

I think the Furrey & Frey Series 1 will be a design classic, at least amongst modellers. Quite distinctive, and definitely robust even scaled down....

[Zomboid]

It's OLE, not OHLE. Overhead is one word.

 

And the GW series 1 is not over engineered. It might be over specified for the short term, but that's a very different thing.