Sanding arrangement

Looking at an Eng dwg of a GWR King I have pinned up at work I note that the pipe from the sand box under the cab goes down close to the rail-head behind the rear driver. The question I have is: how effective is this at getting sand under the wheel, as it looks like the arrangement would always be depositing sand behind the wheel, which would not then be 'run over' by the driving wheel unless the loco rolled back. Wouldn't it be better to blast sand in front of the wheel, so it gets trapped as the wheel rolls forward onto the rail? Does it rely on sand being picked up on the rear of the wheel and carried round as the wheel turns to eventually provide adhesion when that part of the wheel contacts the rail? there must be a reason?

 

I've always thought most locos has at least 1 pair of sand pipes for running in reverse, you would only use that for reverse running of course.

Just had a look at some photos, "Scots" for example had sand pipes in front of the first 2 driving axles for forward running & a pair behind the centre axles for reverse running.

 

You will find that there are both leading and trailing sanders, on Western Locos, the Leading ones are infront of the leading coupled wheels, and the trailing ones, behind the trailing coupled set.
There is a shaft with a series of holes passing through a tube with a simular arrangement to controll the flow.
They are very effective, as long as the sand is dry, wet sand tends to form lumps and block the pipes.

 

Some of the old drivers used to put sand down as they backed onto coaches using the rear pipes for a quick and slip free exit
The melter

 

Used to inferes that people don't bother now!

 

I've done it on occasion when backing on at Bridgnorth on a greasy rail.

 

I've done it on occasion when backing on at Bridgnorth on a greasy rail.[/quote:26g0sqal]
Exactly the situation that crossed my mind!

 

Not sure if they still do it, but a few years ago it was common practice for the crew to hand sand the rails out of Haverthwaite station on wet dank days - not that uncommon in the Lake District! Certainly helped for a good start for the climb up out of the station and into the tunnel.

 

I've done it on occasion when backing on at Bridgnorth on a greasy rail.[/quote:3hudy96b]

Me too, Ade, once you're clear of the point blades on the Cleobury Road bridge, of course! It also helps prevent wheel lock up when backing down on to stock, and those rails can be seriously greasy in the right,(or wrong) conditions.

 

Having working sanders is still part of the daily exam prior to running a railtour.

 

Exactly the situation that crossed my mind![/quote:16rjxfeg]

Most of the crews at Foxfield have sanded when backing onto the train in the days of starting on a 1 in 19 out of the colliery. Now we have the new run-round on the level it is less of an issue. An interesting question though, are we the only railway where working sanding gear is a requirement written into the rule book?

Oh, and in answer to the first question, the sanders you refer to are only designed to be used when the loco is running in reverse! ](*,)

 

See <http://www.raib.gov.uk/cms_resources/080702_R142008_Lydney.pdf> re use of sanders p25-6 in particular about lack of sand

Rob

 

porta recommended that the leading wheels should be sanded as well. i think some of his south american engines had this arrangement fitted. he belieed that the leading sand should be finer than the driving sand, which would have made filling mistakes quite common. he also designed a new tyre which would move the greased sand off the contact surface of the rail

 

there you go one porta wheel profile could this be used in the UK ?http://www.martynbane.co.uk/modernsteam/ldp/adhesion/adhesion.htm