Big yellow arch at DLR bridge

[Deleted]

Hello again

At our Docklands station which is Royal Albert, this week they have put up hugest yellow steel arches on the road each side of the railway bridge, all concreted to the ground, what are these for? Looks as if a bus double decker tried to go through they would break the roof off but there is no bus near here. Must have cost much money and been a big engineering task to make them, obviously something to do with the DLR railway.

[castlebar]

These are in the shape of a big yellow "M"??

I think you are referring to the McDocklands Railway

[Deleted]

Aug 14, 2012 15:19:39 GMT @diana said:

Looks as if a bus double decker tried to go through they would break the roof off...

I think you'll find that is the idea. These tend to go up in areas where there are frequent bridge strikes; it's far preferable that a vehicle hits a free-standing metal girder than the railway bridge.

[Chris M]

If they are over the road leading to the council building from the roundabout then that's curious as double decker rail replacement services negotiate that without any problems. I also don't recall any bridge strikes in the area (although I could easily have missed some).
If there is construction work planned in the area then it is more likely that the bar is positioned high enough to allow buses through but nothing taller. I can't spot anything obvious on the Newham planning permissions site, but then I'm not sure I'd be able to find an elephant in a haystack there.

[Deep Level]

Chris beat me to it there but yes Double Decker Rail Replacement Buses do regularly go under there without an issue.

I too have never heard of a bridge strike here also I'm not sure why this should be a problem as it's not really a through route regularly used by traffic or high lorries and such.

[rincew1nd]

What is the signed maximum height limit? It's been a little while since I've been on one, but I seem to remember something around 14'6" as the height of a double deck bus.

[slugabed]

I believe most Double decker buses are 14'6" plated height.
Bridges have to be plated if their nominal height is less than 16' above the carriageway at any point.
As I understand it,both figures have a safety margin of approx. 6" built in...

[rincew1nd]

Mmmmm, error bars!

[elsombernie]

Aug 14, 2012 17:57:49 GMT Chris M said:

If they are over the road leading to the council building from the roundabout then that's curious as double decker rail replacement services negotiate that without any problems. I also don't recall any bridge strikes in the area (although I could easily have missed some).
If there is construction work planned in the area then it is more likely that the bar is positioned high enough to allow buses through but nothing taller. I can't spot anything obvious on the Newham planning permissions site, but then I'm not sure I'd be able to find an elephant in a haystack there.

I think this may be on the section of road that leads to the canoe club/Chinese restaurant, west of the bus turning 'circle' here.
Perhaps over height vehicles have been trying to access ExCel this way.

[Chris M]

Aug 14, 2012 20:17:33 GMT slugabed said:

I believe most Double decker buses are 14'6" plated height.
Bridges have to be plated if their nominal height is less than 16' above the carriageway at any point.
As I understand it,both figures have a safety margin of approx. 6" built in...

I know that the heights are rounded to the nearest 3in - down in the case of structures and up in the case of vehicles so a 14ft 6in coach will pass under a 14ft 6in bridge with at least 6in spare.

[Deleted]

Mr Castlebar very good, almost as good as Mr D who said they were put up for practising for the Olympic pole voult.

Just to help all the discussions I looked and there is a big sign on the very top which says 4.3m which you will see from upstairs on the double decker just before it hits it, I would have thought it better to put the notice somewhere at the level that a driver would see it.

[trt]

Well, they could do it like they do on the District line and have a glass rod at the top of the bus in line with the fuel line, and on the approach to a low bridge it has to pass under a gauging arch first which would shatter the fuel line of an oversized vehicle, thus stopping it in its tracks. ;-)

[Antje]

Aug 14, 2012 15:28:55 GMT castlebar said:

These are in the shape of a big yellow "M"??

I think you are referring to the McDocklands Railway

You win the internet.

On a serious note, the absence of buses doesn't imply that there is no need for additional safety measures. At 14'3", lorries, particularly tall ones, are at the most risk.

[Deep Level]

Just Google mapped this and it would appear that my memory has deceived me and I think Chris too, I thought the tracks passed over the roundabout exit to the Royals Business Park but instead it cross straight over the roundabout meaning that the part that Diana is referring to is the access to the gym and Royal Albert Dock which is actually past where the Rail Replacement Buses turn around.

[crusty54]

Aug 15, 2012 10:09:35 GMT Chris M said:

Aug 14, 2012 20:17:33 GMT slugabed said:

I believe most Double decker buses are 14'6" plated height.
Bridges have to be plated if their nominal height is less than 16' above the carriageway at any point.
As I understand it,both figures have a safety margin of approx. 6" built in...

I know that the heights are rounded to the nearest 3in - down in the case of structures and up in the case of vehicles so a 14ft 6in coach will pass under a 14ft 6in bridge with at least 6in spare.

not true - nothing like 6" clearance

[bassmike]

I believe that some Routemasters were 14' 8'' over their roof vents,

[castlebar]

bassmike has made a very valid point. London Routemasters may have been 14'6", or 14'8" with roof vents, ONLY on level ground. If the bus is going under a bridge and there is a dip in the road there, it may well be that those measurements apply exactly over the bus wheels, but at the mid-point between the wheels, the bus is actually higher above road level than those measurements. Don't remember who told me but l understand that is why RMLs were banned from some routes such as the old Chiswick to Hayes route 55 which passed under a railway bridge in Acton, because the longer wheelbase made the middle point of the bus even higher. Hanwell garage had loads of RMLs for the 207, but had to get shorter wheelbase RMs just for the 55 as RMLs were banned from the route because of that bridge. I seem to remember it being Acton Lane, just south of the Uxbridge Road. The 55 was ALMOST an RLH route but there weren't enough RLHs made. RTs and RMs were deemed OK, but RMLs were too close to a bridge strike in the making. It MIGHT also have been the case that only non-roof vent RMs were allocated to Hanwell and Turnham Green garages for this route too, but am not certain on that point.

[Dstock7080]

Aug 16, 2012 10:55:35 GMT castlebar said:

Hanwell garage had loads of RMLs for the 207, but had to get shorter wheelbase RMs just for the 55 as RMLs were banned from the route because of that bridge. I seem to remember it being Acton Lane, just south of the Uxbridge Road. The 55 was ALMOST an RLH route but there weren't enough RLHs made. RTs and RMs were deemed OK, but RMLs were too close to a bridge strike in the making.

The 55 gained its RMs when the route moved from Southall into Hanwell garage in October 1965. Hanwell didn't gain it's RMLs for the 207 until September 1967. The 55 was withdrawn in November 1968.

I wholeheartedly agree with the length/height issue with the Acton Lane bridge.

[rincew1nd]

When taking City of York No3 to the Middleton Railway a year or so back we surveyed a new route, we were a little concerned at one particular railway overbridge. The signs prohibited vehicles over 11'5" and wider than 6'6".

We went home and measured the roller, maximum height 10'3"; no problem there. Width, 6'6"; hmmmm. Well we aren't prohibited from going through, lets just hope they measured from the bottom of the kerbs rather than the tops.....

This was the result:


A tight fit by rincewindthefailedwizard, on Flickr


Now I must confess that we did go back with a tape measure which revealed the distance between the bottom of the kerbs to be 7'6", it was still a bit of a squeeze though!

[Deep Level]

That width restriction seems totally unnecessary unless it's to stop HGV's using the route.

[rincew1nd]

I suspect so, the lines above are part of the station throat and any bridge strike would propbably disrupt half of West Yorkshire's rail transport. As it is, any over-height vehicle approaching the bridge breaks a beam (incidentally as does a waved broom handle) which then triggers a multitude of flashing signs advising the approaching vehicle to turn around using the turning circle provided.

I find it interesting that the height restriction is ambidextrous, but that the width is only stated in imperial.

[rincew1nd]

No, ambidextrous; it is sited centrally rather than on either side for left and right-hand drive vehicles. :-p

My rather when referring to the ability to work in both metric and imperial uses the word bisexual.

Anyway, back to the restrictions....

[Deep Level]

Have to agree with railtechnician here :

am·bi·dex·trous/ˌambiˈdekst(ə)rəs/

Adjective:
(of a person) Able to use the right and left hands equally well.
(of an implement) Designed to be used by left-handed and right-handed people with equal ease.

[rincew1nd]

Hmm, I guess its Latin; dexter is right, ambi is both. I guess it follows that there is also ambilevous or would it be ambisinistrous (Roman marching commands were sinister dexter sinister dexter, weren't thry?)

[Deleted]

I was just looking again at the big yellow steel arch that I wrote about at our station Royal Albert and noticed that they have actually put one of the sides - are they called legs - right in the middle of the place made for the special buses we sometimes have at weekends to turn round, just seems silly. So that the bus does not hit it then it has been surrounded all sides by concrete posts sticking up. It is exactly where the buses used to turn around so the space is now smaller than before. We have not had a special bus since this was done and I do wonder will they fit now as often two come together one going each direction.

[rincew1nd]

Aug 17, 2012 11:09:33 GMT railtechnician said:

No problem with a roller, it surely has the power to shave the kerbstones if necessary.

As I alluded above, we were worried that whoever erected the signs had measured the distance between the top of the kerbs rather than at road level; hence our visit with a tape measure, just in case....

It has now become one of our usual routes as, despite gaining a hood, City of York N^o.3 is still under the maximum allowed height. However, with a novice Steersman recently we did prove that concrete kerbs are no match for ten tons of 1927 engineering.


#crumble

[Chris M]

Aug 23, 2012 20:54:27 GMT @diana said:

I was just looking again at the big yellow steel arch that I wrote about at our station Royal Albert and noticed that they have actually put one of the sides - are they called legs - right in the middle of the place made for the special buses we sometimes have at weekends to turn round, just seems silly. So that the bus does not hit it then it has been surrounded all sides by concrete posts sticking up. It is exactly where the buses used to turn around so the space is now smaller than before. We have not had a special bus since this was done and I do wonder will they fit now as often two come together one going each direction.

Making use of my Paralympic travel card, I visited Royal Albert and took some photographs and walked some toe-to-heel measurements (horizontal only).

The bridge in question is the DLR immediately west of Royal Albert station, over Dockside Road (the access road to the regatta centre and Chinese restaurant) Google Street View from June 2012[/img]. The height restriction of 4.3 metres is the same as currently signed on the bridge, when Google visited the restriction was seemingly signed only in imperial 14' 3" (4.343 metres), so it does not appear that the height restriction has been lowered, merely made more obvious.

Rail Replacement buses never pass that way, probably due to the height restriction, but they do use all the turning circle to turn. However, as Diana reported that has been impeeded upon by the northernmost pole for this bridge strike barrier. Even assuming the length of barrier and distance from bridge are fixed, the reduction in available space did not need to be as severe as it is. The following is based on a sketch diagram I drew while I was there. Units of measurement were my size 7 walking boots (units "b" on the diagram), which I've since measured to be approximately 28 cm long to the nearest cm, accurate to approximately half a boot length.


A is the distance between the inner edge of the northern leg and the kerb (19 boots, 5.3 metres) [this seems too large on recollection]
B is the distance from the inner edge of the bollard to the inner edge of the leg.
C is the distance from the outer edge of the northern leg to the southern kerb
D is the length of the barrier, from the outside edges of the legs
E is the distance from the southern kerb to the outside of the southern leg. This seems much greater than it needs to be.
F is the distance from the outside of the southern leg to the edge of the grassy area.

Photos will follow, maybe tomorrow but probably this week.

[Deleted]

Sept 8, 2012 1:31:10 GMT Chris M said:

Making use of my Paralympic travel card...

OT: What did you go to see? I was at the Aquatics Centre evening session yesterday.

[Chris M]

I went to the Paralympics 4 times - a day pass to Excel (Table Tennis, Judo, Sitting Volleyball and Powerlifting), Archery at Woolwich RAB, Wheelchair Rugby at the Basketball Arena (Olympic Park) and the Women's Sitting Volleyball final at ExCeL.

[Deleted]

Sept 8, 2012 1:31:10 GMT Chris M said:

B is the distance from the inner edge of the bollard to the inner edge of the leg.

Hello Mr Chris, do your photographs show that concrete pole B has already been hit and all broken by a big bus or something turning round, I dont think your size 7 walking boots could have done it, must have happened last week end.