British Railways OLE, part one, Plain Track

[David Hibbert]

The welded rod portal was a spare new one made up of metric angles and rod but generally as per the original Mk1 drawing in the 3000 series.

There are many locations where Mk1 (with copper catenary) join Mk3A or B (with aluminium -AWAC- catenary) but the designer has to ensure that the AWAC catenary does not come close to copper catenaries, as the copper washing from ther copper catenary will corrode the aluminium of the AWAC catenary.

[Titan]

Good evening and welcome David!  Been a little while since you were passing a critical eye over my designs!  We used to say that there was the Mk1 range, the OLEMI range and the 'Hibbert' range, which it sounds like this portal falls in!

 

Ian, associate of the late Les Hammond and Peter Hazard!

Edited October 11, 2015 by Titan

[John ks]

I took this picture in Norwich a few years ago, thought it might help.

 

If I was asked where this photo was taken I would have said it was at Dutton Park Brisbane Australia

 

 

The grey building looks like the substation

the building in the background looks like the goods shed that used to be there

The track in the foreground is the line to Cleveland

The track behind it is to Park Rd station

 

QR (Queensland Railways) is a 3' 6" gauge railway with 25Kv OH on almost all of its suburban  lines, some of it main lines heading north from Brisbane

There are also electrified lines from Gladstone & Hay Point to the coal fields

 

The loco is a 25Kv AC Electric destined to pull coal. It was taken during a commissioning run in the late 80's

 

The OH equipment for QR was based on one of the BR system's, possibly MK1 or 2

[markwilson]

Thanks for posting this Clive - it's been fantastically useful to help me position the Dapol Mk3 masts I'm installing on my N Gauge layout - especially the diagram below!

 

 

[DavidMcKenzie]

Thanks Clive, a huge amount of useful info posted here

[DaveClass47]

Hi Clive

 

I’m using head-spans on my Dean Park station layout. It’s based on the ECML in late 1980’s/early 90’s. 

 

Ive got a stretch of track (about 3m) where putting in the Mk3a Dapol masts would be tight. As I will have a retaining wall dropping away at oNe side to track lower down and a depot at the other side. Check the layout out on YouTube to get an idea.

 

my question is... were single masted OHLE structures as in the photo used in the early days of the ECML or are these designs more modern? The photo was taken at Edinburgh in October 2019. 

 

I want ant to know if I can get away with using this type of structure for a layout in the late 1980’s on the ECML

 

Please advise 

thanks. 

Dave

[Pete the Elaner]

14 hours ago, DaveClass47 said:

 

my question is... were single masted OHLE structures as in the photo used in the early days of the ECML or are these designs more modern? The photo was taken at Edinburgh in October 2019. 

 

I want to know if I can get away with using this type of structure for a layout in the late 1980’s on the ECML

 

 

In the absense of a definitive reply...

 

If it looks ok to you, then model it.

The portal itself would not look out of place with Mk1 catenary, but the rest looks like Mk3.

I am fussier than most (but not all) & wouldn't think it was wrong for somewhere done as part of the ECML scheme.

[Clive Mortimore]

8 hours ago, Pete the Elaner said:

In the absense of a definitive reply...

 

If it looks ok to you, then model it.

The portal itself would not look out of place with Mk1 catenary, but the rest looks like Mk3.

I am fussier than most (but not all) & wouldn't think it was wrong for somewhere done as part of the ECML scheme.

Oi You!!! I have been busy today I can't spend my time playing on here.

 

 

23 hours ago, DaveClass47 said:

Hi Clive

 

I’m using head-spans on my Dean Park station layout. It’s based on the ECML in late 1980’s/early 90’s. 

 

Ive got a stretch of track (about 3m) where putting in the Mk3a Dapol masts would be tight. As I will have a retaining wall dropping away at oNe side to track lower down and a depot at the other side. Check the layout out on YouTube to get an idea.

 

my question is... were single masted OHLE structures as in the photo used in the early days of the ECML or are these designs more modern? The photo was taken at Edinburgh in October 2019. 

 

I want ant to know if I can get away with using this type of structure for a layout in the late 1980’s on the ECML

 

Please advise 

thanks. 

Dave

To answer Dave's question. It is a Mk3 twin cantilever so is fine for a the period you are modelling.

 

The do look like Mk1 structures but dimensionally are different. This one is of particular interest, the track closest to the platform has above it  slow speed tramway registration arms, the two arms form the center of overlap combined with a low structure height. Is there a bridge behind the photographer? The outer track has mix of headspan and standard cantilever parts also with a low structure height. They normally look like the attached drawing , which I have incorrectly called a half gantry. I cannot say the cantilever is dimensionally correct. Since drawing it I do have a copy of the BR drawing for this type of mast but haven't updated my old drawings.

[DaveClass47]

1 hour ago, Clive Mortimore said:

Oi You!!! I have been busy today I can't spend my time playing on here.

 

 

To answer Dave's question. It is a Mk3 twin cantilever so is fine for a the period you are modelling.

 

The do look like Mk1 structures but dimensionally are different. This one is of particular interest, the track closest to the platform has above it  slow speed tramway registration arms, the two arms form the center of overlap combined with a low structure height. Is there a bridge behind the photographer? The outer track has mix of headspan and standard cantilever parts also with a low structure height. They normally look like the attached drawing , which I have incorrectly called a half gantry. I cannot say the cantilever is dimensionally correct. Since drawing it I do have a copy of the BR drawing for this type of mast but haven't updated my old drawings.

Hi Clive. That diagram is exactly what I had in mind, similar but. I exactly the same as the photo I took on Wednesday. 

 

Behind me was the Edinburgh Waverley canopy/roof. 

 

Your diagrams for the mk3a headspans were a crucial for me when building my own ones. 

 

Ill certainly be having a good think about your diagram and perhaps modifying the nbrass portals to model these. 

Cheers

Dave

[DaveClass47]

10 hours ago, Clive Mortimore said:

Oi You!!! I have been busy today I can't spend my time playing on here.

 

 

To answer Dave's question. It is a Mk3 twin cantilever so is fine for a the period you are modelling.

 

The do look like Mk1 structures but dimensionally are different. This one is of particular interest, the track closest to the platform has above it  slow speed tramway registration arms, the two arms form the center of overlap combined with a low structure height. Is there a bridge behind the photographer? The outer track has mix of headspan and standard cantilever parts also with a low structure height. They normally look like the attached drawing , which I have incorrectly called a half gantry. I cannot say the cantilever is dimensionally correct. Since drawing it I do have a copy of the BR drawing for this type of mast but haven't updated my old drawings.

I assume this type of mast would be okay for high speed main lines?! Or would they be head span?

[Clive Mortimore]

10 hours ago, DaveClass47 said:

I assume this type of mast would be okay for high speed main lines?! Or would they be head span?

They are suitable for main lines, they are sited where it is not possible to place two single cantilever mast, restricted places etc. They are also used where a more specialist mast is required.  On the upgrading of the WCML a similar design with UK1 fittings replaced quite a few single cantilever mast that had gone wonky.

[DaveClass47]

On 18/10/2019 at 22:41, Clive Mortimore said:

Oi You!!! I have been busy today I can't spend my time playing on here.

 

 

To answer Dave's question. It is a Mk3 twin cantilever so is fine for a the period you are modelling.

 

The do look like Mk1 structures but dimensionally are different. This one is of particular interest, the track closest to the platform has above it  slow speed tramway registration arms, the two arms form the center of overlap combined with a low structure height. Is there a bridge behind the photographer? The outer track has mix of headspan and standard cantilever parts also with a low structure height. They normally look like the attached drawing , which I have incorrectly called a half gantry. I cannot say the cantilever is dimensionally correct. Since drawing it I do have a copy of the BR drawing for this type of mast but haven't updated my old drawings.

Hi Clive, sorry to ask another question, but that diagram had struts at the end shown in blue coming down to support the horizontal wire. What does that look like from the end elevation? Struggling to find an example of it. Do the struts come from each side of the portal lattice and meet in a type of inverted triangle design, where they connect to and support the wire?

 

any photos of these guys greatly appreciated:-)

Thanks

Dave

[Clive Mortimore]

It is triangular,

 

 

[DaveClass47]

4 hours ago, Clive Mortimore said:

It is triangular,

 

 

Perfect! Thanks Clive. 

[daveyb]

On 05/05/2013 at 06:03, Dagworth said:

Ah yes, the first 86 into Ilford...

Pan has its height limit set for WCML equipment, locos tries to drive into ICS, pan goes up with the wire, pan reaches its overheight trip and comes down in a hurry... loco stops requiring assistance... 

After that all the GE 86s had to have their overheight settings tweaked to cope with the high wires.

 

EMUs don't have overheight switches, the pan will keep raising until it breaks its back.

 

Andi

Wasn't there a similar issue when they named an 86 Sir John Betjeamin on Platform 7/8 at old St. Pancras?

[DavidMcKenzie]

Hi Clive, 

 

I was slowly trying to get my head around the OLE for a new layout and firstly I must thank you, this series of posts has been a wonderful help to me. I have question with regards to the vertical legs (sorry if I have used the wrong term). The photo below shows the two different types I have built (one is higher because it won't be mounted on the platform). I've managed to build the gantries without really noticing that they were different. Would there be any relevance to the two types? Would one or other only be used in specific locations? I am modeling a section from the end of a station into a tunnel if it has any bearing. I won't confess to ever getting the model perfect, but I do enjoy learning about the real thing as I go and try not to do anything that's too obviously wrong so any help would be much appreciated. 

 

 

All the best,

Dave

[spenc]

On 07/05/2021 at 21:15, DavidMcKenzie said:

Hi Clive, 

 

I was slowly trying to get my head around the OLE for a new layout and firstly I must thank you, this series of posts has been a wonderful help to me. I have question with regards to the vertical legs (sorry if I have used the wrong term). The photo below shows the two different types I have built (one is higher because it won't be mounted on the platform). I've managed to build the gantries without really noticing that they were different. Would there be any relevance to the two types? Would one or other only be used in specific locations? I am modeling a section from the end of a station into a tunnel if it has any bearing. I won't confess to ever getting the model perfect, but I do enjoy learning about the real thing as I go and try not to do anything that's too obviously wrong so any help would be much appreciated. 

 

 

All the best,

Dave

Hi Dave

I have started building gantrys I cut the bottom  of the posts off as instructed so to fit on the platform posted on my thread one of the comments said it looks too high so confused to the corrected height with platform mounted gantrys.  

[Clive Mortimore]

On 07/05/2021 at 21:15, DavidMcKenzie said:

Hi Clive, 

 

I was slowly trying to get my head around the OLE for a new layout and firstly I must thank you, this series of posts has been a wonderful help to me. I have question with regards to the vertical legs (sorry if I have used the wrong term). The photo below shows the two different types I have built (one is higher because it won't be mounted on the platform). I've managed to build the gantries without really noticing that they were different. Would there be any relevance to the two types? Would one or other only be used in specific locations? I am modeling a section from the end of a station into a tunnel if it has any bearing. I won't confess to ever getting the model perfect, but I do enjoy learning about the real thing as I go and try not to do anything that's too obviously wrong so any help would be much appreciated. 

 

 

All the best,

Dave

Both are right. The important measurement is the height of the contact wire from the rail top, everything else fits around that.

Here are some examples of Mk1 portals on platforms. The important thing with any mast mounted on platforms is there is no live electricity over the platform. With the over bridge catenary one registration arm is reversed to give a negative stagger

 

 

[Magna Junction]

On 04/05/2013 at 22:15, Clive Mortimore said:

Until last year I had a website that covered 25 KVa OLE, the host company changed things and I let the site die. I have considered doing a new site but today following the discussion on the Dapol OLE thread http://www.rmweb.co.uk/community/index.php?/topic/16442-Dapol-announce-oo-ole/ I decided to put a modified version of the website on here in a series of threads. I am modeller who has never worked for the railways therefore my information has been gleaned form what sources of information I have been able to get my hands on therefore I hope that other members on here can add to the threads with further information.

 

Much of the information will be historic as my own interests do not go much beyond the 1980s so I welcome any information on newer systems.

 

Plain track

 

I will describe the overhead wiring for a section of plain track without any point work, bridges, stations etc.

 

Stagger.

 

The wires on plain track are held above the line normally by cantilever mast, arranged so that the contact wire zigzags as it goes along. This is called stagger, and is arranged in this fashion to create even ware on the pantograph of the locomotives and multiple units.  The cantilever mast are positioned opposite each other on twin track, there is a push off assembly which holds the contact wire away from the centre line towards the centre of the two tracks. Above the other track is a pull off assembly that pulls the contact wire towards the outside of the track. The distance from the centre line of the track and the position of the contact wire at the registration point (where it is held by the mast) is 9ins for Mk1 OHLE and 230mm for Mk3. If working in 4mm scale this is 3mm.

 

Contact Wire Height.

 

With Mk3 equipment the contact wire height is 4.7m, slightly lower than Mk1 which is 16ft or 4.864m. This height can vary where there are level crossings, over bridges, depots and yards.  With early overhead schemes the height was greater in station areas as well. All these variations will be covered later.

 

 

This photo shows the stagger. Note the alternative use of push-off and pull-off mast. This is non-typical Mk1 cantilever mast using round post as found on the Chelmsford to Colchester section of the GE line. Photo taken on a level crossing at Kelvedon.

Mast Spacing

 

The distance between each mast is called the span. Masts are spaced the maximum distance apart where possible. The maximum design span is 73m (958mm in 4mm scale),and the minimum is 13m (170mm in 4mm scale). Were mast are of unequal distance apart the difference between them must not be over 20m (262mm).  There are many governing factors, which determine the distance for each span, these include the physical layout of the railway, where the points and junctions are, over bridges, under bridges and viaducts, stations, signals, gradients etc. Another important factor on the real railway is side wind, not a problem with model railways but one worth considering if you are modelling a line going across exposed fells or the fens. When the span is being calculated the “blow off”, sideways displacement of the contact wire due to strong wind should not allow the wire to go outside the pantograph sweep and the two loose contact with each other.  So in areas of high cross winds the spans are reduced in length.

 

Types of Overhead

 

Fixed Termination Equipment

 

This is found on older systems like the GER suburban lines and where wire runs are short, e.g. terminus stations. The contact wire is pre tensioned and is supported either end by heavy anchor mast.  This type of equipment is preferred on tight curved track as balanced weighted equipment cannot overcome the loads imposed by drag from the pantograph.  

 

Automatic Tensioned Equipment

 

This more commonly found and uses balance weights each end to keep the tension preventing the contact wire from moving out of place due to temperature changes, wind, and displacement by the pantograph of a moving train. In the centre of each length of wire is an anchor point, without this the wire would creep towards one balance weight due to being pulled along by the pantograph.

 

 

Tension Length and Number of Mast

 

On automatic tensioned equipment the maximum length is 1970m, from the anchor mast in the centre to each overlap at the ends there should be 14 masts. Where the mast are closer than this the wire length is shorter, the number of mast is the governing factor not the length of wire run until 1970m is reached. Crossovers, sidings, loops etc have shorter lengths with less than 14 masts from anchor point to balance weight.

 

The distance between the overlaps on the GER suburban lines is approximately 1 mile. There are 28 masts from one end to the other. Due to the contact wire being fixed at each end there is no need for a mid point anchor.

 

Mk1 and Mk3 mainly used cantilevers on single and double line plain track. The older 1500v DC systems of the GER and Woodhead route used portals.

 

Using the above information if your model layout has no points, obstructions etc and the track is straight then provided the number of mast is less than 14 the overhead will be cantilevers set as to give a stagger spaced at a maximum of a scale 73m.  Most model railways are not that simple, we like our stations with their sidings, loops etc. We also like bridges and tunnels, and most of us have sections of curved track.

 

Even if the layout was just a section of plain twin track how nice it would be to model a mid point anchor, or an overlap or even a feeder station.

 

 

 

 

 

 

Hi Clive,

 

Having ordered Accurascale's Class 89 ive turned my attention to planning for some scratchbuilt OHLE.

 

Ive looked through your brilliant diagrams of different OHLE but can't seem to find any MK3 Headspan diagrams.

 

Think I can remember looking at them before.

 

Any chance you could repost?

 

Regards

 

Scott.

[96701]

This document might be useful to some. There are sketches and photos of different types of GB OLE (no H, Overhead is one word).

 

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/930123/use-of-gb-mainland-overhead-line-equipment-ole-support-structures.pdf

[Ravel]

Thought it was best to ask here,

 

I am planning to build a model based loosely on somewhere between Crewe and Cheadle Hulme, there are a number of "gantry" style portals dotted about, are these drawn to specific site requirements or is there a generic design that is just adapted?

 

I don't seem to be able to find many dimensions, other than height, for 2 track "half gantry's". I've measured a couple on Google Maps and they appear to be roughly between 9.7m to 11m in width across two tracks.  Cess to Cess measurements appears to be anywhere between 9m to 11m, so I guess they can't be much bigger than that?

[4700mm]

On 20/01/2024 at 17:00, Ravel said:

Thought it was best to ask here,

 

I am planning to build a model based loosely on somewhere between Crewe and Cheadle Hulme, there are a number of "gantry" style portals dotted about, are these drawn to specific site requirements or is there a generic design that is just adapted?

 

I don't seem to be able to find many dimensions, other than height, for 2 track "half gantry's". I've measured a couple on Google Maps and they appear to be roughly between 9.7m to 11m in width across two tracks.  Cess to Cess measurements appears to be anywhere between 9m to 11m, so I guess they can't be much bigger than that?

 

Structures are designed to the requirements of the site. Designers use a general arrangement drawing and select the parts needed for their requirements, the height of the portal and the length of the portal boom will vary from structure to structure.