Renew the rail network and save the planet

On 2005-06-22, Austin Shackles <[email protected]> wrote:

> Mind, I suspect the newfangled tar emulsion that they use is not as
> sticky as the tar used to be, and I'm also convinced that the
> chippings they use now are too large.

There was some programme on recently with the tidy Fiona Bruce
presenting it, a popular road surface amongst councils has been found
to be as slippery when dry as it is when it's wet, at least until it's
been worn in. Something to do with a binding agent melting when the
car goes over it and lubricating the tyre/road interface.

Mind you one council fixed the problem by mixing grit in with the
emulsion so perhaps the large chippings you are seeing are the
solution ;-)

--
For every expert, there is an equal but opposite expert

On or around Wed, 22 Jun 2005 08:07:59 +0100, Ian Rawlings
<[email protected]> enlightened us thusly:

>On 2005-06-22, Austin Shackles <[email protected]> wrote:
>
>> Mind, I suspect the newfangled tar emulsion that they use is not as
>> sticky as the tar used to be, and I'm also convinced that the
>> chippings they use now are too large.
>
>There was some programme on recently with the tidy Fiona Bruce
>presenting it, a popular road surface amongst councils has been found
>to be as slippery when dry as it is when it's wet, at least until it's
>been worn in. Something to do with a binding agent melting when the
>car goes over it and lubricating the tyre/road interface.
>
>Mind you one council fixed the problem by mixing grit in with the
>emulsion so perhaps the large chippings you are seeing are the
>solution ;-)

In the old days, they spread tar on the road, applied a layer of small
(about 10-12mm) chippings, and rolled them into the tar with a big roller.
Now they spread tar emulsion, apply larger chippings and still roll it, the
overall effect is utter crap. I reckon it's a combination of effects:

1) tar emulsion may not be as sticky as plain tar
2) tar emulsion makes a thinner layer on the road
3) larger chippings don't adhere so well in the thinner layer of tar
4) larger chippings create more leverage on the bond at the base when
subjected to sideloads, such as created when cornering.

By contrast, the hot-rolled macadam system where small chippings are mixed
with tar and then spread by the big spready-machine, and then rolled, while
presumably more expensive, produces a superior road surface which lasts for
ages.

I question how much more expensive it is, at that - consider:

1) the raw materials are much the same - chippings and tar
2) the raw materials have to be transported to the site
3) the roller is the same
4) the spreading machine is extra, but the tar spreading tanker is absent

I suppose somewhere there's a huge machine that makes the mixture in the
first place, to put in the tippers that bring it to be spread. But overall,
I doubt it costs as much as double, (or I doubt that it *should*) and it
produces a road that lasts much longer.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

On 2005-06-22, Austin Shackles <[email protected]> wrote:

> I suppose somewhere there's a huge machine that makes the mixture in the
> first place, to put in the tippers that bring it to be spread. But overall,
> I doubt it costs as much as double, (or I doubt that it *should*) and it
> produces a road that lasts much longer.

Given the way the highway authorities treat green lanes -- use the
cheapest resurfacing method possible that lasts less than a year
despite the 15-year alternatives not costing 15 times as much -- I
expect it's the intense short-termism to blame. What's the point in
them spending our money wisely when they're not likely to be around to
get the votes, err I mean thanks..

--
For every expert, there is an equal but opposite expert

On Wed, 22 Jun 2005 10:37:44 +0100, Austin Shackles wrote:

> In the old days, they spread tar on the road, applied a layer of
> small (about 10-12mm) chippings, and rolled them into the tar with a
> big roller.
<snip>
> By contrast, the hot-rolled macadam system where small chippings are
> mixed with tar and then spread by the big spready-machine, and then
> rolled, ...

Ah but the first is really just a thin surface treatment on top of a
worn surface layer and can be applied several times before the road
needs to be planed and relaid.

The second requires the old surface layer to be removed by surface
planing for a couple of inches and then the new macadam laid. If you
don't drains and man hole covers become hollows and kerb stones are
half height.

--
Cheers [email protected]
Dave. pam is missing e-mail

On or around Wed, 22 Jun 2005 17:07:34 +0100 (BST), "Dave Liquorice"
<[email protected]> enlightened us thusly:

>On Wed, 22 Jun 2005 10:37:44 +0100, Austin Shackles wrote:
>
>> In the old days, they spread tar on the road, applied a layer of
>> small (about 10-12mm) chippings, and rolled them into the tar with a
>> big roller.
><snip>
>> By contrast, the hot-rolled macadam system where small chippings are
>> mixed with tar and then spread by the big spready-machine, and then
>> rolled, ...
>
>Ah but the first is really just a thin surface treatment on top of a
>worn surface layer and can be applied several times before the road
>needs to be planed and relaid.

Point is though that the surface of the hot-rolled takes MUCH longer to
wear.


>The second requires the old surface layer to be removed by surface
>planing for a couple of inches and then the new macadam laid. If you
>don't drains and man hole covers become hollows and kerb stones are
>half height.

good point, but then they use the resultant debris for filling hollows in
verges and the like. It does add to the cost of doing it, I guess. But I
bet it's still cheaper long-term and produces better results.

--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Quos deus vult perdere, prius dementat" Euripedes, quoted in
Boswell's "Johnson".

Peter <[email protected]> schreef in berichtnieuws
[email protected]...
> One freight train removes 40 HGVs from the road and consumes 20% of the
> fuel.
> Make long distance truck delivery (say over 50 miles) illegal and use road
> vehicles for short drops from strategically placed new railheads built to
> serve the public rather than the shareholders. It's so simple, the
> government couldn't grasp it. The only people to disagree with this are
the
> road hauliers with their own pockets to line.
> British rail was far more efficient on a tiny subsidy than the privatised
> cowboys and they killed hundreds less passengers!
> Peter
>
>
Seen on the back of a truck:

Without trucks the roads would be empty -
so would be your refridgerator.

nuff said.

I'm a railway signaller (signalman) so I agree!

Ron


"Patrick en Antoinette" <[email protected]> wrote in message
news:[email protected]...
>
> Peter <[email protected]> schreef in berichtnieuws
> [email protected]...
>> One freight train removes 40 HGVs from the road and consumes 20% of the
>> fuel.
>> Make long distance truck delivery (say over 50 miles) illegal and use
>> road
>> vehicles for short drops from strategically placed new railheads built to
>> serve the public rather than the shareholders. It's so simple, the
>> government couldn't grasp it. The only people to disagree with this are
> the
>> road hauliers with their own pockets to line.
>> British rail was far more efficient on a tiny subsidy than the privatised
>> cowboys and they killed hundreds less passengers!
>> Peter
>>
>>
> Seen on the back of a truck:
>
> Without trucks the roads would be empty -
> so would be your refridgerator.
>
> nuff said.
>
>
>