Re: [greenwichcyclists] Greenwich Council and that grit
- Dear Greenwich cyclists...
"Silica sand" is a *finely ground* silicate, and the sand you find on
the beach is largely silica. What I spent several minutes picking out
of my tyre treads last weekend looked like shards of crushed green
bottle glass. Not the stuff you find on the beach, or the industrial
product that sometimes goes by the name "silica sand". Some of the
shards were a few millimetres across – i.e., large enough to cause
injury to, say, a small child who falls over and lands on them.
The "Greenwich Council spokesperson" is lying.
On 11 Feb 09, at 18:19, ANTHONY AUSTIN wrote:
> Dear Greenwich Cyclists
> Thank you for your comments about the use of silica sand mixed with
> rock salt on some hard surfaces in the borough. I regret that I was
> unable to open the images one of you sent.
> I am surprised that you found sharp pieces in the mixture. The
> Council used the mixture for two reasons: in order to give a better
> grip on slippery surfaces, and to make the salt go further. The
> substance we used is recycled silica used as a substitute for sand.
> It should not contain dangerously sharp pieces, and I could find
> none in the samples I have examined. Moreover, the operatives who
> mixed it with rock salt and those who spread it did not detect any
> particles sharper than what would be expected in coarse sand.
> I realise that all sand can be abrasive and that it could graze
> people's skin in the event of a fall. However, the abrasiveness of
> the substance is, in part, what makes it effective as an anti-slip
> agent. Please rest assured that the Council is keen to promote
> cycling and our primary concern was to make footways safe for
> pedestrians and other roads users. We will certainly bear your
> comments in mind for the future.
> We have now resumed normal sweeping and any residual sand will be
> cleared as part of this process. I would anticipate that the
> majority of the grit will be cleared by the end of this week, and I
> have asked the Area Manager to check on the progress of the work.
> Greenwich Council spokesperson
Dr Francis Sedgemore
journalist and science writer
- Further on this ...The following comes from a Report by the Chief Executive of the council (from: http://charltonaverage.blogspot.com/) about their work during the "freeze":"2.5. In addition, we have sourced an additional stock of 20 tonnes of 'glass sand' (made from recycled glass) from Days Aggregates on Greenwich Peninsula. We have mixed this with salt to make it available for use on hard surfaces away from the public highway, eg schools, parks, entrances to Council services etc."So it was glass - and not very well ground by the look of it...John