On Apr 18, 12:19*am, Charles Ellson
wrote:
In this evening's news it seems "that somebody must be done" and that
the existence of scrapyards under railway lines is to be investigated
(but no mention of various other businesses possessing inflammable or
explosive substances under hundreds of railway arches).

Or indeed just local pubs with leaky gas pipes under tram viaducts.

In message , at 08:58:49 on Mon, 18 Apr
2011, d remarked:
What I can't quite follow with the M1 closure is why they can't allow
cars and not lorries, and set up a speed restriction. Or do they think
it would be too difficult to enforce?

Probably the latter. Unless you put up physical width restrictions on the
carraigeway you're going to have to permantly have a plodsworth waving trucks
and buses off at junction 4. Which doesn't sound like a safe job. Or I
suppose you could ANPR and just fine them heavily but they'll still drive
over the damaged bridge so it won't help.

Having one or two Highways Agency bods (plod doing this is so 20th
Century) waving cars past a temporary chicane is a small price to pay
for re-opening in these circumstances.
--
Roland Perry

On Mon, 18 Apr 2011 10:52:12 +0100
Roland Perry wrote:
Having one or two Highways Agency bods (plod doing this is so 20th
Century) waving cars past a temporary chicane is a small price to pay
for re-opening in these circumstances.

FWIW I agree with you. But it would require planning and organisation in a
short time period. Not something the highways agency or its contractors
seem particularly good at. Give them 2 months notice and they might manage
it.

B2003

In message , at 10:48:28 on Mon, 18 Apr
2011, d remarked:

Having one or two Highways Agency bods (plod doing this is so 20th
Century) waving cars past a temporary chicane is a small price to pay
for re-opening in these circumstances.

FWIW I agree with you. But it would require planning and organisation in a
short time period. Not something the highways agency or its contractors
seem particularly good at. Give them 2 months notice and they might manage
it.

They stuck a van across the M1 to create a diversion round the fire much
quicker than that (you must have seen it in the TV coverage). Add
another van and you've got the checkpoint. The M1 already has speed
limit and lane-closure signs.
--
Roland Perry

Charles Ellson wrote:
On Sun, 17 Apr 2011 12:04:29 +0100, "Peter Masson"
wrote:
"Charles Ellson" wrote

The early morning news showed it closed southbound with some traffic
running northbound.

One northbound lane reopened on Saturday evening, but the viaduct needs
propping up, and teh southbound side isn't expected to reopen until Monday
morning.
http://www.bbc.co.uk/news/uk-england-london-13107189

In this evening's news it seems "that somebody must be done" and that
the existence of scrapyards under railway lines is to be investigated
(but no mention of various other businesses possessing inflammable or
explosive substances under hundreds of railway arches).


There are not many businesses whose owners would wish to locate them
under motorway viaducts, or in arches under an operating railway.
Landowners who wish to encourage businesses to rent in these locations
means that they will often accept whoever they can get.

Scrap yards are particularly undesirable tenants because of the
presence of acetylene and oxygen cylinders and vapour in fuel tanks of
vehicles sent for scrap. Perhaps a planning guidance note will be all
that is required to prevent scrap yards or other risky businesses
being established in these locations in future. The difficult issue
is how to deal with those that are already there.

"Roland Perry" wrote in message
...
In message , at 10:48:28 on Mon, 18 Apr
2011, d remarked:

Having one or two Highways Agency bods (plod doing this is so 20th
Century) waving cars past a temporary chicane is a small price to pay
for re-opening in these circumstances.

FWIW I agree with you. But it would require planning and organisation in a
short time period. Not something the highways agency or its contractors
seem particularly good at. Give them 2 months notice and they might manage
it.

They stuck a van across the M1 to create a diversion round the fire much
quicker than that (you must have seen it in the TV coverage). Add another
van and you've got the checkpoint. The M1 already has speed limit and
lane-closure signs.

But you probably end up causing more congestion trying to separate cars
which can go along the damaged motorway from trucks that can't, than having
everything take the diversion. I doubt that you could safely set up physical
width restrictions on a motorway, as has been done to restrict this weak
railway bridge to cars and other light traffic
http://www.newsshopper.co.uk/news/88...t_Road_bridge/

Peter

In message , at 23:24:22 on
Mon, 18 Apr 2011, Peter Masson remarked:

But you probably end up causing more congestion trying to separate cars
which can go along the damaged motorway from trucks that can't, than
having everything take the diversion.

It's what they do routinely for contraflows. Which are clearly better
than closing the motorway completely.

I doubt that you could safely set up physical width restrictions on a
motorway, as has been done to restrict this weak railway bridge to cars
and other light traffic
http://www.newsshopper.co.uk/news/88...__pressing_ahe
ad__to_replace_Chislehurst_Road_bridge/

You are confusing long term physical measures with something a bit
simpler to get the traffic moving *now*. There's no need for a width
restriction as such, what you are doing is segregating HGVs.
--
Roland Perry

"Roland Perry" wrote

You are confusing long term physical measures with something a bit simpler
to get the traffic moving *now*. There's no need for a width restriction
as such, what you are doing is segregating HGVs.

In a contraflow it doesn't matter too much if an occasional HGV gets in the
narrow lane, though it might add to congestion. If an HGV goes across a weak
bridge or viaduct it might well add to the deterioration of the structure,
resulting in a lengthy closure to all traffic. So in these circumstances
signs need to be supplemented by physical measures (e.g. physical width
restrictions) which would not be appropriate on a motorway.

Peter

In message , at 08:57:25 on
Tue, 19 Apr 2011, Peter Masson remarked:

You are confusing long term physical measures with something a bit
simpler to get the traffic moving *now*. There's no need for a width
restriction as such, what you are doing is segregating HGVs.

In a contraflow it doesn't matter too much if an occasional HGV gets in
the narrow lane, though it might add to congestion. If an HGV goes
across a weak bridge or viaduct it might well add to the deterioration
of the structure, resulting in a lengthy closure to all traffic. So in
these circumstances signs need to be supplemented by physical measures
(e.g. physical width restrictions) which would not be appropriate on a
motorway.

You are making it over-complicated, and appear to have forgotten the
Highways Authority bod supervising the road.

ps If you are really convinced that only a physical barrier would work,
then it would most easily take the form of a height limit.
--
Roland Perry

In uk.transport.london message , Mon, 18
Apr 2011 08:58:49, d posted:

Probably the latter. Unless you put up physical width restrictions on the
carraigeway you're going to have to permantly have a plodsworth waving trucks
and buses off at junction 4. Which doesn't sound like a safe job. Or I
suppose you could ANPR and just fine them heavily but they'll still drive
over the damaged bridge so it won't help.

All that is needed is to put across the carriageway, at the entrance to
where lorries are not wanted, a nice stout RSJ at a height of, say, 2 or
2.5 metres. Or a simulated row of standard prefab domestic garages,
with the doors and back walls removed. Or a row of miniature Nissen
huts, without ends; the walls/roofs stack easily for transport, and
light beams can be bolted from top to top for steadiness.

On top, erect a suitably-painted canvas screen, to be conspicuous.

--
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