Model of an epicyclic gear made by apprentices

[Henry BrownParticipant @henrybrown95529]

This was a medium sized gear Dave, the chap in the photo was about 6'3". It took a bit longer than 5 minutes to cut the teeth on these

[John HaineParticipant @johnhaine32865]

Sorry, jokey reference to another thread!

[Howard LewisParticipant @howardlewis46836]

Going off thread, the mention of crankcase explosions, filled me with fear. Read a book on main propulsion engines and there was a photo of the after effects of one in an engine with two staircases leading from bedplate level to cylinder head. Both were twisted like paper clips!

Apparently, the rate of pressure rise was such that the varnished brown paper bursting discs, intended to guard against such things, failed too slowly to prevent damage.

I witnessed one from across a car park in a motorway service area. Sudden bulge in bonnet, and clouds of smoke, from a car which had screamed down the motorway and entered the car park at about 70 mph with tyres screaming, before switching off

A colleague worked at Blackstones when they were trying to develop "explosion proof" crankcase doors. Apparently, seeing a door weighing over a hundred weight flying across the shop was something e!se.

Another colleague was standing beside an engine on test when it suffered a crankcase explosion. The sump fell onto the bedplate, leaving the flange still securely bolted to the underside of the crankcase!

There is a two cylinder Allen diesel engine, with various windows, motored as an exhibit, at The WaterWorks Museum, in Hereford.

Howard

[Martin ConnellyParticipant @martinconnelly55370]

This is a parallel gearbox as supplied to Rustons, latterly Siemens. The flange with the plywood over it was the take-off for the lubricating oil pump. The other is the input from the starter motor. The input from the turbine was on the far side. The turbine power shaft was at the other end of the turbine.

Martin C

[Henry BrownParticipant @henrybrown95529]

Posted by Henry Brown on 03/10/2021 21:37:49:

This was a medium sized gear Dave, the chap in the photo was about 6'3". It took a bit longer than 5 minutes to cut the teeth on these

Not sure what happened there – it showed the pix as I was typing the comments, so lets have another go…

Howard, I'll pop in to the Museum and have a look at that Allen twin next time I'm over there…

[Henry BrownParticipant @henrybrown95529]

Typical Allen Gears supplied to Siemens…

[Rik ShawParticipant @rikshaw]

I grew up as a child in Queens Park (AKA Slopers Island), Bedford the home of WH Allens Queens Works where some of the best medium/heavy engineering in the world was crafted.

My little old granny from rural Wiltshire was tickled pink when she first saw the hundreds of workers bikes flooding into Ford End Road at dinner time (lunch was for toffs back in the 'fifties) and every working man in those days seemed to be wearing an old demob mac

My old mate Tab remembers his National Service time in the navy and the respect held for the reliability of Allens engines, turbines, gearboxes etc. He told me that when his ship was underway two armed guards were posted either side of the main gearbox hatch to prevent sabotage to the Allens made gear within.

Although the factory is no longer in Queens Park the spirit lingers on in Bedford where service engineers are still dispatched around the world to fettle Allens kit.

**LINK**

[Henry BrownParticipant @henrybrown95529]

Great memories Rik…

I remember as a new apprentice going to Bedford and being amazed at the size of some of the machines they had, one thing that stands out in my memory was a couple of us standing in one bore of an in line eight cylinder engine block!

Sadly the engine manufacturing moved to Scandinavia as part of the Rolls Royce rationalisation and now the gears are made in France after RR sold the business at Pershore to three directors who made a right cods of it, finally selling it on to GE who, despite owning Lufkin, had no idea about manufacturing high speed, high power epicyclics. I'm told it took the French engineers eighteen months to get a working gear despite having all the drawings.

[Martin ConnellyParticipant @martinconnelly55370]

Gearboxes in position of the sort shown in the "Typical Gearboxes…" photo.

Martin C

[Henry BrownParticipant @henrybrown95529]

A test bed build picture at Lincoln I presume Martin?

[Martin ConnellyParticipant @martinconnelly55370]

Not test bed. These are contract builds.

Martin C

[Henry BrownParticipant @henrybrown95529]

Posted by Martin Connelly on 04/10/2021 18:15:50:

Not test bed. These are contract builds.

Martin C

Interesting, the first part of the jigsaw was the gearbox, central point so logical I guess. Unfortunately I didn't ever get to Siemens at Lincoln, my main contact was through Greenray as I latterly worked in the Service department. I did get involved with a few of the technical people when things went wrong though…

All good stuff, thanks Martin.

[Martin ConnellyParticipant @martinconnelly55370]

The fabrications were levelled using rules on the machined features and dumpy levels to the as machined position then benchmarks were fitted all round, you can see theses as small rectangular plates on the fabrications. These allowed the package to be levelled on site when the machined features had things on them or were obscured by enclosures etc. The gearboxes were then placed on the fabrications and aligned then drilled, reamed and dowelled to lock them in position. They became the datum for positioning the turbines on the fabrications. The fabricators made a small block with a groove and welded them on the end, one can be seen on one of the photos. We usually had to ignore these and replace them with another benchmark plate in order to get the required tolerances of position and to assist with package alignment on site. Often the last major part to be added was the turbine, sometimes they were shipped without the turbine and that was fitted on site.

Martin C

[Nigel McBurney 1Participant @nigelmcburney1]

Reading about Blackstone engines,and crankcase explosions I am glad that my two Blackstones are open crank,

[Howard LewisParticipant @howardlewis46836]

There is single cylinder open crank Blackstone, a runner, at The WaterWorks Museum in Hereford.

From the presence of a Dobbie McKinnies indicator and provision for a Prony brake, it probably came from a Technical College.

Hope to drive over there, for a days volunteering on Sunday 17th, which suspect will be the last working Sunday for 2021.

Some of the last cast iron sumps seen outside at Stamford.were large enough to use as a coffin! Larger than the ones to which I was accustomed.

Howard

[Author]

Posts