Level Crossings & OHLE

[brianthegiant]

Are vehicle level crossings with height restrictions allowed under overhead line equipment?
I suspect not, certainly for new lines/new electricification?
So does this mean that any roads crossing the Midland Mainline on the level would need to be replaced with bridges prior to electrification?
would be interesting in the Long Eaton / Attenborough area...
(no mention of crossing closures on Nottingham spur in the CP document that I'm aware of).

 

[Ploughman]

As a PW man and not OHLE but have worked around it a lot I would sat that if possible, subject to wire gradients etc, the clearance would be lifted as high as possible on LC's. I would consider equivalent to motorway bridge clearance as a start if not more.
I would suspect that if any particular crossing is a regular abnormal load route then that would be taken into consideration as part of the project.

 

[Bald Rick]

Are vehicle level crossings with height restrictions allowed under overhead line equipment?
I suspect not, certainly for new lines/new electricification?
So does this mean that any roads crossing the Midland Mainline on the level would need to be replaced with bridges prior to electrification?
would be interesting in the Long Eaton / Attenborough area...
(no mention of crossing closures on Nottingham spur in the CP document that I'm aware of).

Yes sort of.

And OLE can (and will) be put up over existing LX.

Generally, the contact wire is set to its highest permitted height at LX (best part of 6m ???), which is why any picture of a train over an LX will have the pantograph fully extended.

But LX are certainly not (normally) permitted on new lines.

 

[DavidBrown]

In terms of road vehicles, the standard height for OHLE above a level crossing is 16 foot 6 inches (as the warning signs approaching such a crossing state). The minimum height for a motorway bridge (or any other bridge that's not defined as a "low bridge") is 16 foot.

 

[snowball]

In terms of road vehicles, the standard height for OHLE above a level crossing is 16 foot 6 inches (as the warning signs approaching such a crossing state). The minimum height for a motorway bridge (or any other bridge that's not defined as a "low bridge") is 16 foot.

No, the Traffic Signs Manual, chapter 4, page 29, section 7.7, says that all bridges and other structures with a headroom less than 16'-6" should be signed. So vehicles just under 16-'6" can expect to wander around the road system safely if they pay attention to the signs. So presumably the standard height for OHLE at a level crossing is somewhat more that 16'-6" to allow electrical clearance.

Indeed the relevant Railway Group Standard says that the minimum OHLE height at a level crossing without height gauges is 5600mm, which is 18'-4.5".

For all I know there may be a standard design height which is supposed to be used if readily achievable and is greater than 18'-4.5".

Anyone know what's the highest a pantograph is required to be able to stretch?

 

[G_A_C_C_C]

I'd like to see what they are going to do at Bourne End when they electrify the line to Marlow. The level crossing into the Marina is used to get quite large boats in and out on trailers and some quite large cranes in and out to lift the boats from/to the water.

Not a chance they will fit under the OHLE.

 

[brianthegiant]

might be a bit 'hair-raising' for the crane driver... I witnessed a crane getting stuck under a 33kV line once.. thankfully no arcing but the poor guy just had to sit in the cab nervously until the network operator isolated the line.

it transpired the road had been built after the ohl & the clearances didn't comply so the line had to be changed to underground.

 

[deltic1989]

I'd like to see what they are going to do at Bourne End when they electrify the line to Marlow. The level crossing into the Marina is used to get quite large boats in and out on trailers and some quite large cranes in and out to lift the boats from/to the water.

Not a chance they will fit under the OHLE.

Maybe a similar thing to what I have seen in Holland (but may be done elsewhere) when the railway crosses a swing bridge or drawbridge (not the same thing as an LC but hear me out ) . What they do is stop the wires just before and restart them just after, so that there are no wires over the obsticle (in this case an LC) and the train just coasts along the un-wired section which in the case of an LC would be 10 maybe 20 metres.

 

[michael769]

might be a bit 'hair-raising' for the crane driver... I witnessed a crane getting stuck under a 33kV line once.. thankfully no arcing but the poor guy just had to sit in the cab nervously until the network operator isolated the line.

Most mobile cranes are quite a bit lower than the highest trucks when fully retracted. The largest Liebherr mobile crane the LTM 11200-9.1 is only 4m high in road going trim (5.025m with an optional swing out boom):

 

[lincolnshire]

Most mobile cranes are quite a bit lower than the highest trucks when fully retracted. The largest Liebherr mobile crane the LTM 11200-9.1 is only 4m high in road going trim (5.025m with an optional swing out boom):

Nice picture as long as it keeps its jib down

 

[michael769]

Nice picture as long as it keeps its jib down

HIAB drivers are terrible for forgetting and hitting bridges, petrol station canopies (a particular favourite for them) and the like, but the mobile crane operators have extensive safety training and are somewhat less likely to make that mistake.

 

[MarlowDonkey]

I'd like to see what they are going to do at Bourne End when they electrify the line to Marlow. The level crossing into the Marina is used to get quite large boats in and out on trailers and some quite large cranes in and out to lift the boats from/to the water.

Not a chance they will fit under the OHLE.

I'm wondering whether they won't reconsider the Bourne End to Marlow stretch when they get round to detail planing and drop it as too much trouble. As well as the access crossings, there's also the problem of the short platform at Bourne End used for access to the Marlow branch. What future that leaves is uncertain, closure or a legacy diesel service presumably.

 

[dysonsphere]

Nice picture as long as it keeps its jib down

I seem to recall 4M is the clearance required in a large part of Euorpe, our 16'6" is the higest in the EEC so much so they tried to ban the higher trucks a few years ago.

 

[Haydn1971]

The Highways Agency ddesign guidence DMRB requires that a clearance of 5.3m is provided on new over bridges, 5.7m on footbridges and other structures vulnerable to vehicle impact (I'd consider OHLE in that category) and 6.45m on high load routes - all plus consideration for sag curves.

The requirements of the ORR could well be different now but there used to be a requirement for 5.6m clearance to 25Kv at level crossings (5.5m for 1500Kv DC and upto 25Kv AC). But interestingly the HSE state a figure of 5.2m for safe power cable clearance.

Nothing in engineering design is ever easy

 

[brianthegiant]

But interestingly the HSE state a figure of 5.2m for safe power cable clearance.

btw your figure of 5.2 m only applies to <=33kV not on roads, definitions for roads & higher voltages given in :
www.legislation.gov.uk/uksi/2002/2665/schedule/2/made

detailed clearances for National Grid assets also here:
www.nationalgrid.com/uk/LandandDevelopment/DDC/devnearohl_final/appendixIII/appIII-part2

 

[balne-wonderer]

Interesting stuff. On the ECML near Doncaster there is a planned project to remove a level crossing at Joan Croft, replace it with a road bridge which will allow the cables to be lowered as they no longer need to higher than the highest road vehicles plus a safety margin. I'm sure it was worded like that.

Of course, the bigger picture is the new jct they are putting in at Joan Croft but I was interested to find out the regs on OHLE at level crossings.