Why are London Double Decks taller than Double Decks Outside the Capital

[J-2739]

Good morning, hope you all have a lovely Sunday,

One thing that's always clued me up is how double deckers in London are generally ordered to the highbridge spec (4.4m), compared to DDs outside the capital (around 4.2m).

Why is this the case?

I suspect Tfl specifying it, but something else? And why wouldn't operators outside try to go for the more comfortable 4.4m highbridge bus? I'm suspecting lower bridges outside the capital, but that fails when you realize that the buses made here are delivered by road (or is it?), not to mention the bountiful London cast offs.

Can't wait to here some comprehensive answers from each and every one of you!

 

[GusB]

Double deckers are such a rarity in my area these days, that I hadn't honestly given much thought to the difference between full-height and low-height deckers. Back in pre-privatisation days, NBC/SBG decker purchases tended to be of the low-height variety (Ailsa/Volvo Citybus aside), so I'm assuming that low bridges must have been an issue in some places.

My local route used to have double deckers allocated on a regular basis, and while there are no issues with low bridges, there is certainly a problem with low trees.

I'm reminded of an incident that happened not too long ago near Inverness, when a decker struck a low bridge (in this case the bridge was 11'3", so no decker would have been appropriate!).

https://www.pressandjournal.co.uk/fp/news/inverness/748113/bridge-ripped-top-off-of-bus-after-driver-forgot-he-was-driving-a-double-decker/

 

[carlberry]

Good morning, hope you all have a lovely Sunday,

One thing that's always clued me up is how double deckers in London are generally ordered to the highbridge spec (4.4m), compared to DDs outside the capital (around 4.2m).

Why is this the case?

I suspect Tfl specifying it, but something else? And why wouldn't operators outside try to go for the more comfortable 4.4m highbridge bus? I'm suspecting lower bridges outside the capital, but that fails when you realize that the buses made here are delivered by road (or is it?), not to mention the bountiful London cast offs.

Can't wait to here some comprehensive answers from each and every one of you!

TfL specify the vehicles and the extra height makes them less attractive afterwards as it's important to a lot of operators. It's not just bridges, a couple of years ago a London spec decker had it's roof ripped off in Bristol because of low trees on a service that happily uses lower height deckers.

 

[J-2739]

TfL specify the vehicles and the extra height makes them less attractive afterwards as it's important to a lot of operators. It's not just bridges, a couple of years ago a London spec decker had it's roof ripped off in Bristol because of low trees on a service that happily uses lower height deckers.

Hmm, I see. On my bus route to school, there are so many low trees and yet the route uses double decker buses. Can be a fright when sitting at the front!

Could use guard rails I suppose, though that must be expensive and not really blocking out thicker trees.

 

[J-2739]

Double deckers are such a rarity in my area these days, that I hadn't honestly given much thought to the difference between full-height and low-height deckers. Back in pre-privatisation days, NBC/SBG decker purchases tended to be of the low-height variety (Ailsa/Volvo Citybus aside), so I'm assuming that low bridges must have been an issue in some places.

My local route used to have double deckers allocated on a regular basis, and while there are no issues with low bridges, there is certainly a problem with low trees.

I'm reminded of an incident that happened not too long ago near Inverness, when a decker struck a low bridge (in this case the bridge was 11'3", so no decker would have been appropriate!).

https://www.pressandjournal.co.uk/fp/news/inverness/748113/bridge-ripped-top-off-of-bus-after-driver-forgot-he-was-driving-a-double-decker/

Double deckers are rare in my area also, so I also didn't pay attention to the differences. The East Lanc Vykings in our area are so awkwardly low.

I guess London has less bridges and trees to worry about.

 

[ECML180]

I imagine that a few inches difference in height has aerodynamic implications, probably saves a fair bit of fuel over a vehicles life.

But I think trees is a strong arguement - TfL are very pro-bus whereas much of the rest of the country is neutral at best. In my local area there is a route where single deckers can strike trees, a while back I was sat on one and a good foot or so of branch came in an open window and snapped off. After a network change that now has deckers which can really struggle to pass some trees, which I have never seen get trimmed in years of living here. Likewise some other trees elsewhere are noticably shaped like a double decker bus, presumably having been 'trained' into that shape by repeated strikes. One school route I've driven out in the countryside hadn't seen deckers for years, and no matter what at some points you would have to drive extremely slowly, listening for the tree to move around the deck and not through the windows! I can imagine that again for this a little change in height can reduce the risk profile quite a way.

 

[daikilo]

I agree that trees are important. Many decades ago, the school bus would take a short-cut on my way home. At a particular point on the journey, most drivers would be in the centre of the road. One day, a vehicle was coming in the other direction and he didn't with the resulting almighty crash from the upper deck as a very substantial branch reshaped the roof of the Bristol LD/FS.

Some time before that, on the morning run which was usually a Bristol LD or occasionally a lowbridge K, we had a highbridge K. As I took an interest in buses I was intrigued by which route we would take when at the village a few miles down the road, after which was a rail bridge too low for high-bridge buses. The bus was nearly full as, in the village, we pulled out onto the normal route and shortly after passed the last avoiding road; I remember running down the stairs and warning the conductor. He didn't question whether I should be believed but was on the bell imediately. We were late for school as reversing the thing a couple of hundred yards, against the traffic, was a challenge.

In those days, a tree-cutting decker would pass by occasionally on official bus-routes, but I never saw one raising bridges.

 

[AM9]

I suspect that TfL, with its relationships over the years with the GLA/GLC/LCC has been in a position to insist that trees on its routes are kept well trimmed. Add to that the generally high frequencies of services, the trees had little chance of growing back into the path of buses.
From my days of living in the central bus area, RTs, (over 4000 of them), were 14ft 6in high and most overbridges always seemed to be 15ft + high so they had little problems, particularly as deviations from the routes authorised by the traffic commissioners needed official approval which I assumed included the buses' equivalent of gauge clearance. Also, the sheer volume of London suburban traffic has over the years tended to sweep away most of the arched overbridges that required high vehicles to take a centre of the road line under them as most of them seem to now be steel spans with flat undersides.

 

[philthetube]

When councils ran bus services they used to take a lot more care over trees and many companies had buses converted to tree lopping duties.

 

[Busaholic]

I suspect that TfL, with its relationships over the years with the GLA/GLC/LCC has been in a position to insist that trees on its routes are kept well trimmed. Add to that the generally high frequencies of services, the trees had little chance of growing back into the path of buses.
From my days of living in the central bus area, RTs, (over 4000 of them), were 14ft 6in high and most overbridges always seemed to be 15ft + high so they had little problems, particularly as deviations from the routes authorised by the traffic commissioners needed official approval which I assumed included the buses' equivalent of gauge clearance. Also, the sheer volume of London suburban traffic has over the years tended to sweep away most of the arched overbridges that required high vehicles to take a centre of the road line under them as most of them seem to now be steel spans with flat undersides.

The 4000 or so Central RTs, supplemented by 2131 RTLs/RTWs, had interlopers in the case of lowbridge Regents classified RLH, an order placed by East Midland Omnibus Co and diverted if my memory's correct. There weren't many of these (by London standards) and they operated in Harrow, Worcester Park and Upminster. Later on, when the 127 route was withdrawn after the road under Worcester Park bridge was lowered, these buses were transferred to Dalston to convert the Clapton Pond to Stratford route from single deck. The 178 was the last RLH route, converted in 1971 to one person single deck.

 

[randyrippley]

, but that fails when you realize that the buses made here are delivered by road (or is it?), not to mention the bountiful London cast offs.

The Borismasters (and other Wrights buses) come from Ireland on the ferry via Heysham. The only bridge they had to go under to reach the M6 was the Lune Aqueduct, which has plenty of headroom. Now the new Bay Gateway bypass is open all the bridges they have to pass under are built to motorway standards, so theres no physical restrictions until the new buses reach London.

 

[philthetube]

there are, of course, other ways to get buses under low bridges.

https://www.google.co.uk/search?q=b...ei=Ld6OWNvEKYa4afnTvIAG#imgrc=KIqF7LVNk2SKTM:

 

[ChrisPJ]

A little simplistic to state that only London buys new full height double deck buses, many other operators have done and still do.

 

[Hophead]

A little simplistic to state that only London buys new full height double deck buses, many other operators have done and still do.

Agreed - I would like a few more facts regarding the numbers of low-height vs full-height buses outside of London. I've not noticed this preference myself, although that's just from observation rather than many miles of travel (so others are better qualified to say).

I can say, however, that TfL specifically mandates full-height double-deckers. In the past, some operators did introduce low-height vehicles, I seem to remember, but this did not meet with official approval. The rules were amended I think.

 

[daikilo]

Agreed - I would like a few more facts regarding the numbers of low-height vs full-height buses outside of London. I've not noticed this preference myself, although that's just from observation rather than many miles of travel (so others are better qualified to say).

I can say, however, that TfL specifically mandates full-height double-deckers. In the past, some operators did introduce low-height vehicles, I seem to remember, but this did not meet with official approval. The rules were amended I think.

This nomenclature is misleading because a low-floor decker can provide full standing height on both the main and upper decks. I suspect the TfL reauired height actually goes back to e.g. the Routemaster which had a step up to the lower deck and thus reduced clear height on both decks.

 

[Mikey C]

This nomenclature is misleading because a low-floor decker can provide full standing height on both the main and upper decks. I suspect the TfL reauired height actually goes back to e.g. the Routemaster which had a step up to the lower deck and thus reduced clear height on both decks.

I imagine that London DDs have far more people standing in them though, and for longer journeys.

From memory Stagecoach have always ordered low height double deckers for outside London, and they're usually longer than the London ones as well - I remember some of the late model Volvo Olympians they operated in London before the high floor ban had a provincial low height spec so that they could be transferred out.

 

[J-2739]

Anyone have any photos of low height DDs and high height DDs next to each other? Will be good to see the difference!

A little simplistic to state that only London buys new full height double deck buses, many other operators have done and still do.

I didn't say 'only'. I said 'generally', as per my original post.

 

[ChrisPJ]

You said London generally orders 4.4m high buses and suggested that everywhere else was 4.2. I'm just pointing out that the latter isnt the case in a lot of places!

 

[carlberry]

You said London generally orders 4.4m high buses and suggested that everywhere else was 4.2. I'm just pointing out that the latter isnt the case in a lot of places!

If we're being pedantic the original post said 'around 4.2m', not specifically 4.2m

It's still the case that the vast majority of vehicles bought new outside London are specified at low height whereas TfL (partly because London always has to be difficult or different (and sometimes both) requires full height.

 

[randyrippley]

Surely highbridge designs were only relevant for old step entrance designs? I would have assumed modern low floors render them irrelevant

 

[ChrisPJ]

Really? Stagecoach certainly did and maybe still does but who else?

 

[Goldfish62]

If we're being pedantic the original post said 'around 4.2m', not specifically 4.2m

It's still the case that the vast majority of vehicles bought new outside London are specified at low height whereas TfL (partly because London always has to be difficult or different (and sometimes both) requires full height.

Why is requiring standard height double deckers being difficult? And that does also make the operators outside London who order standard height double decks also difficult? FirstBus for example.

 

[Goldfish62]

TfL specify the vehicles and the extra height makes them less attractive afterwards as it's important to a lot of operators. It's not just bridges, a couple of years ago a London spec decker had it's roof ripped off in Bristol because of low trees on a service that happily uses lower height deckers.

Obviously not considered a problem given that First's more recent deliveries in Bristol are all standard height (ie not low height).

 

[Busaholic]

If we're being pedantic the original post said 'around 4.2m', not specifically 4.2m

It's still the case that the vast majority of vehicles bought new outside London are specified at low height whereas TfL (partly because London always has to be difficult or different (and sometimes both) requires full height.

Without the London orders, there'd only be one (at best) double deck bus manufacturer in the UK.

 

[GusB]

Without the London orders, there'd only be one (at best) double deck bus manufacturer in the UK.

I'm not quite sure that I would agree with you, but I'd be interested to find out which manufacturer you think would still be around.

 

[TheGrandWazoo]

Why is requiring standard height double deckers being difficult? And that does also make the operators outside London who order standard height double decks also difficult? FirstBus for example.

In the North East, there were historically three main operators (and they arguably still exist in the same form). TWPTE and Northern (Stagecoach and Go Ahead) largely specified full height deckers though Northern did have a few 4.2m deckers. United however specified 4.2m deckers as standard. The reason being the number of lower bridges that were encountered especially in South West Durham and Northumberland associated with the mines.

Seem to recall that Potteries had a lot of 4.1m (13'5) VRs because of the number of low bridges in their operating area.

 

[johnw]

Stagecoach always order low height. Divisions such as United Counties always had them due to low bridges in Kettering and Bedford.

 

[SpacePhoenix]

I think that Wilts & Dorset always ordered lower height ones, higher ones might have bashed their roofs at Poole Bus Station

 

[Busaholic]

I'm not quite sure that I would agree with you, but I'd be interested to find out which manufacturer you think would still be around.

I'm going on Buses magazine's annual collation of bus and coach manufacturer's data, which has been going a long time (twenty years?) and there was certainly one year (if not two) where their conclusion was that, without those London orders d.d. construction would finish; this was fairly soon into the low-floor era, but I can't quote actual years. The ownership of bus manufacturers has also changed since those days, so to name that one company could be misleading. All I'm prepared to say is that it's most certainly not Wrightbus!

 

[GusB]

I'm going on Buses magazine's annual collation of bus and coach manufacturer's data, which has been going a long time (twenty years?) and there was certainly one year (if not two) where their conclusion was that, without those London orders d.d. construction would finish; this was fairly soon into the low-floor era, but I can't quote actual years. The ownership of bus manufacturers has also changed since those days, so to name that one company could be misleading. All I'm prepared to say is that it's most certainly not Wrightbus!

I think if there was only going to be one survivor, it would have been Alexander. Twenty years ago there certainly weren't many companies building 'deckers. MCW had gone and I think Leyland had ceased production at Workington. That would have left Alexander, NCME and East Lancs from the "old school" and Optare, which was building the Spectra. Wright's hadn't introduced the Gemini by then.

I know that Alexander was supplying to London at that point, but I'm not sure of the numbers. They still had orders from Stagecoach and I know that Lothian were still taking new vehicles on a fairly regular basis. I'm not really certain about the situation south of the border. Of course, there was also the overseas business from Hong Kong and Singapore.

I think we're quite lucky to be where we are now in terms of the number of manufacturers that exist.