The Classic Machinery Network

Hello,
Here are two photos of filling the shaft at Deep Navigation Colliery,Treharris.This was the deepest shaft in The Coal Field.
1st photo.the Cat 211 is filling the shaft, the dump truck is a DJB.
2nd.photo. a fleet of DJB's waits to tip.
The 38 R-B shovel is demolishing the compressor house at Merthyr Vale Colliery (Aberfan). And what about Wimpey's classic AEC Mamoth Major Tipper.

Fred.

Hi
Sorry photos. in wrong order again. Wheres the eddit button gone?[url]:?: [/url]

Hi Fred, dont worry about the order of the pictures, i am sure every one will work it out

How deep was the shaft Fred ?

Martyn

Hi Martyn
Not realy worried about the pics.
The shaft was about .75 of a mile deep. It had a slight bend in it, and was notorious for giving a rough ride to anyone riding the cage.
My company did a lot of concrete work to the top of the shaft in 1985 to allow the coal to be brought up in skips and onto a conveyor instead of the traditional method using drams.
An NCB engineer friend of mine told me there was enough coal down there for another 70 years
when it was closed.

The shaft was about .75 of a mile deep

Thats a hell of a depth Fred ... and is it right that it takes many years for the shaft backfill to settle ... what depth was the bottom of the cap ?

Martyn

Great pics ,its nice to see the old gear in colour , like the AEC .

XS650 wrote:Great pics ,its nice to see the old gear in colour , like the AEC .

Seconded

Steve

Thirded

Martyn Henley wrote:

The shaft was about .75 of a mile deep

Thats a hell of a depth Fred ... and is it right that it takes many years for the shaft backfill to settle ... what depth was the bottom of the cap ?

Martyn

Hi Martyn.Thank you All.
You are right the back-fill does settle over time. I dont know about the thickness of the concrete cap on this one. They were usualy about 1m. thick. We did a couple.
The first one I was involved with at Elliots Colliery, New Tredegar, was 750 mm thick and heavily reinforced.(25mm. bar)
It had been designed without a vent and one night there was what local people discribed as an earth tremmor.
The back-fill had been erroded from the bottom of the shaft by water and dropped suddenly.
The vacum caused had sucked the cap a few meters into the shaft. It had the appearance of the inside of an egg shell that had been tapped with a spoon. The lesson was learned and all future caps were vented.
Fred

Fowler man, these are fascinating pics my favourite being the wimpey shovel and djbs full of rubble- your description of the vacuum caused by the settling of the fill is also of great interest to me- please please please could you share these pics over on the aditnow.co.uk mining forum -theres a topic on shaft capping i feel would greatly benefit from your description as many were debating the many other purposes of shaft vent pipes aside from releasing gases ,