Block, Strap, Gib and Cotter

Advert

New Replies

Report Bug

Help/FAQs

Block, Strap, Gib and Cotter

This topic has 37 replies, 19 voices, and was last updated 25 November 2017 at 21:09 by peak4.

Viewing 25 posts - 1 through 25 (of 38 total)

1 2 →

Author

Posts
22 November 2017 at 16:06 #328493
Colin LLoyd
Participant
@colinlloyd53450
At the beginning of the 2nd WW, my father, a young and newly qualified Toolmaker & Fitter left Archdale's Engineering Works in Worcester to join the Royal Navy. The entrance practical exam at Portsmouth Dockyard for Engine Room Artificers included making a Block, Strap, Gib and Cotter in 42 hrs using only a hammer, chisel and 3 files using no machinery except for drilling holes. I've attached a photo I've found of this type of test piece.

My questions are: what are, or were, Block, Strap, Gib and Cotter and what were they used for. And why were they used to test entrants to the Royal Navy at the start of the 2nd World War?
Advert

22 November 2017 at 16:06 #35060
Colin LLoyd
Participant
@colinlloyd53450
22 November 2017 at 16:27 #328496
Neil Wyatt
Moderator
@neilwyatt
I would guess those would be used for tensioning standing (steel wire) rigging.

Similar arrangements used to be used to adjust bearings.

Neil
22 November 2017 at 16:56 #328506
John Haine
Participant
@johnhaine32865
I remember reading a biography of Geoffrey de Havilland who was a Cranwell apprentice I think, and apparently thay has a test of making a mating nut and bolt using only cold chisel hammer and files. I suppose it might just be possible… I suppose that you'd have to make a tap for the internal thread.
22 November 2017 at 16:59 #328509
SillyOldDuffer
Moderator
@sillyoldduffer
They're used to connect rods together that are only subject to axial forces. Normally a block is made on the end of one rod and the strap on the other.

The rod and strap are both traversed by a slot. To assemble the fastener, the block and strap are aligned and the 'u' shaped gib inserted so that it's ends lock on the strap. Finally the wedge shaped gib is hammered into the remaining gap to lock the whole together.

The advantage is that the joint can be assembled and dismantled quickly whilst keeping the parts in the same relative position. Once common on locomotives to connect rods to cross-heads and elsewhere to fix rods to stationary parts.

Your picture (which I've decluttered) is the first I've seen with screw-threads. Possibly this is because they are apprentice pieces rather than the real thing.

My dad joined the RN to train as an Artificer at the end of 1945. He never mentioned any practical exams on entry. Possibly the RN dropped the 'make it with a chisel' test because WW2 didn't have time to waste when most warships were fitted with turbines or diesels. Possibly because it was moved down the curriculum. (Dad was invalided out after a year due to a rugby injury. Near miss for me – that's how he met my mum!)

Dave

Edited By SillyOldDuffer on 22/11/2017 17:01:11
22 November 2017 at 18:38 #328532
Muzzer
Participant
@muzzer
Talking of funny rope-related names, I was initially surprised to see one of these described as a "thimble". Funny folk, sailors.

Murray
22 November 2017 at 18:58 #328536
Neil Wyatt
Moderator
@neilwyatt
Posted by Muzzer on 22/11/2017 18:38:55:

Talking of funny rope-related names, I was initially surprised to see one of these described as a "thimble". Funny folk, sailors.

Murray

I can tell you aren't a 'sea-scouty type'

Neil
22 November 2017 at 19:02 #328538
Neil Wyatt
Moderator
@neilwyatt
I've shown this before, similar arrangement of strap, gip and cotter to hold a bearing in place:
22 November 2017 at 19:23 #328544
Muzzer
Participant
@muzzer
Posted by Neil Wyatt on 22/11/2017 18:58:10:

I can tell you aren't a 'sea-scouty type'

Neil

Hmm, actually that's where I learnt about all that stuff. When I was in my early teens, we lived near the sea on Belfast Loch (during The Troubles) and I became very interested in sailing, amongst other things. Obviously my Scottish parents weren't about to buy me a boat so the only way to get my hands on one was through the local Sea Scouts – cue silly hats, whistles, marching about etc. Learning all the knots and parts of the boats was a piece of wind and soon I was out and about in their boats (mainly Mirrors) during the weekends and evenings. Did my RYA Dayboat certificate etc and a few minor events before my dad closed down the local ICI plant (Kilroot, manufacturing PET) and we moved back to God's Country.

Murray
22 November 2017 at 19:59 #328555
Neil Wyatt
Moderator
@neilwyatt
Please accept my grovelling apologies!

I assumed you had only just learned what a thimble was. I'll hank a sack of ropes and do twenty back-splices as atonement!

I did a lot of time on Mirrors and occasionally a Heron. Mostly kayaking though, started on wood and rubberised canvas ones but latterly mostly Snipes IIRC which were great fun for surf canoeing (my record was 13 capsizes in one day…)

Neil
23 November 2017 at 11:45 #328639
Vic
Participant
@vic
Interesting question Colin and thanks for posting the picture. It’s nice to see the basic forgings (if that’s what they are are) next to the finished components. It seems to be to tension something but I’m a bit surprised that no one on here has been able to give you a concise answer yet.
23 November 2017 at 16:48 #328708
Colin LLoyd
Participant
@colinlloyd53450
My father also noted that this exercise separated those "engineers" with only machine training (e.g. lathes and milling machines) from those that could turn their hand to anything. He didn't know what the things were until he examined one of the early locomotives of the Canadian National Railway at Halifax, Nova Scotia after his ship's (HMS Malaya) crossing of the Atlantic with gold bullion on board destined for safe keeping in Fort Knox (27th Feb – 4th Mar. 1940).

Speaking of lathes – he also told a tale that illustrates the British attitude to war. During one of the many Mediterranean actions that HMS Malaya was involved in, my father went ashore and found an abandoned German lathe. He got the rest of the engine room artificers to row to shore, load the lathe onto the boat with some difficulty and row back to the ship. With difficulty, the lathe was winched up the side of the battleship where the ship's Captain was waiting (hidden). As my father put his head over the side, the Captain said "Lloyd – is that lathe yours? The reply was "No". "Lloyd – you will return it to where you found it". So different from the Nazi attitude to personal items.
23 November 2017 at 17:16 #328713
Tim Stevens
Participant
@timstevens64731
The reason that apprentices were given such tasks was not because they were likely to be a regular part of their later life. They were tasks which included a variety of hand and tool skills, requiring in addition a degree of organisation, and discipline. Knowing that anyone passing the test was able to produce stuff – any stuff, not obsolete steam engine fittings – using these skills was a big encouragement to employers.

Is that the sort of answer that will suit?

Cheers, Tim
23 November 2017 at 19:04 #328728
Neil Wyatt
Moderator
@neilwyatt
Posted by Tim Stevens on 23/11/2017 17:16:13:

The reason that apprentices were given such tasks was not because they were likely to be a regular part of their later life. They were tasks which included a variety of hand and tool skills, requiring in addition a degree of organisation, and discipline. Knowing that anyone passing the test was able to produce stuff – any stuff, not obsolete steam engine fittings – using these skills was a big encouragement to employers.

Is that the sort of answer that will suit?

Cheers, Tim

In a previous job we introduced an assignment as part of some of our recruitment; it was to see if people could produce a decent, if short, piece of written work in response to a relevant scenario given quite a brief length of time – 20-30 minutes.
23 November 2017 at 23:05 #328780
Georgineer
Participant
@georgineer
Posted by Neil Wyatt on 23/11/2017 19:04:46:

In a previous job we introduced an assignment as part of some of our recruitment; it was to see if people could produce a decent, if short, piece of written work in response to a relevant scenario given quite a brief length of time – 20-30 minutes.

I was given an assignment like that in the mid-seventies when I went for a job with one of the big engineering companies. The answer came back that they didn't have a vacancy that suited my skills, but they had passed my details on to their research establishment . After a further interview I ended up working there instead.

George
24 November 2017 at 07:50 #328798
Russell Eberhardt
Participant
@russelleberhardt48058
Posted by Colin LLoyd on 22/11/2017 16:06:05:

At the beginning of the 2nd WW, my father, a young and newly qualified Toolmaker & Fitter left Archdale's Engineering Works in Worcester to join the Royal Navy. The entrance practical exam at Portsmouth Dockyard for Engine Room Artificers included making a Block, Strap, Gib and Cotter in 42 hrs using only a hammer, chisel and 3 files using no machinery except for drilling holes. I've attached a photo I've found of this type of test piece.

He must have had great skill to be able to produce those screw threads with just a hammer, chisel, and files

Russell
24 November 2017 at 15:07 #328883
Colin LLoyd
Participant
@colinlloyd53450
Posted by Russell Eberhardt on 24/11/2017 07:50:08:

Posted by Colin LLoyd on 22/11/2017 16:06:05:

At the beginning of the 2nd WW, my father, a young and newly qualified Toolmaker & Fitter left Archdale's Engineering Works in Worcester to join the Royal Navy. The entrance practical exam at Portsmouth Dockyard for Engine Room Artificers included making a Block, Strap, Gib and Cotter in 42 hrs using only a hammer, chisel and 3 files using no machinery except for drilling holes. I've attached a photo I've found of this type of test piece.

He must have had great skill to be able to produce those screw threads with just a hammer, chisel, and files

Russell

Unfortunately, I only began to transcribe his war memoirs after he died. Or else I would have asked him the same question – along with many others that arose during my attempt to read his difficult hand-writing.
24 November 2017 at 15:19 #328886
MW
Participant
@mw27036
Posted by Russell Eberhardt on 24/11/2017 07:50:08:

He must have had great skill to be able to produce those screw threads with just a hammer, chisel, and files

Russell

Oh, those pre-war types, skill unsurpassed to this day, now that was chiselling within an inch of your life. 14tpi to be exact.

Michael W
24 November 2017 at 15:22 #328887
Colin LLoyd
Participant
@colinlloyd53450
Posted by Muzzer on 22/11/2017 18:38:55:

Talking of funny rope-related names, I was initially surprised to see one of these described as a "thimble". Funny folk, sailors.

Murray

I have no idea why they are called thimbles – but they were an essential part of the long steel cables I used to support tall aluminium scaffold towers that I built over both UK forests and tropical rain forests in Brazil and Cameroon – the tallest being 52m high, 27 sections each 2m x 1.5m x 1.96m tall. Photo shows one of the towers in J–Parana, Rondonia, Brazil.
24 November 2017 at 15:26 #328888
KWIL
Participant
@kwil
The same could be said of the standard apprentice piece, the 1 inch cube and the hole through which it had to pass (just). Good eye, steady hand and attention to detail. 'nuff said?
24 November 2017 at 15:30 #328890
KWIL
Participant
@kwil
Neil,

Do you still have your Marlin Spike then?
24 November 2017 at 16:22 #328909
Gordon Tarling
Participant
@gordontarling37126
As apprentices (apprentii?), we were required to produce a '3 way fit' – circle square and triangle piece had to fit into the appropriate holes in a piece of 1/4 steel plate. Some made it look easy, but many struggled, including myself.
24 November 2017 at 16:49 #328920
Neil Wyatt
Moderator
@neilwyatt
Posted by KWIL on 24/11/2017 15:30:46:

Neil,

Do you still have your Marlin Spike then?

I left it stuck in a horse's hoof

Of all the things I have lost over the years my ex-Army knife with blade, bottle/can opener and marlin spike is one of the most missed. Much more rugged and therefore much more useful than a Swiss Army Knife.

Neil
24 November 2017 at 16:50 #328921
Neil Wyatt
Moderator
@neilwyatt
Posted by Colin LLoyd on 24/11/2017 15:22:08:

Posted by Muzzer on 22/11/2017 18:38:55:

Talking of funny rope-related names, I was initially surprised to see one of these described as a "thimble". Funny folk, sailors.

Murray

I have no idea why they are called thimbles – but they were an essential part of the long steel cables I used to support tall aluminium scaffold towers that I built over both UK forests and tropical rain forests in Brazil and Cameroon – the tallest being 52m high, 27 sections each 2m x 1.5m x 1.96m tall. Photo shows one of the towers in J–Parana, Rondonia, Brazil.

Phew – I knew you researched forest canopies but rather you than me on that one!

Neil
24 November 2017 at 17:32 #328930
Mick Henshall
Participant
@mickhenshall99321
In my apprenticeship we fitted a "Tee Block" and an" Octogen" into a block of mild steel 1" thick using only bench tools can't remember how many fits there were for each one but they were numerous. Mine were exhibited in a model engineering exhibition (my Gramps was the Chairman). There were some apprentices from Winfrith Nuclear est. there who could not believe I had't used machines, I explained that at sea machines were usually absent although a lathe was usually carried

Mick
Author

Posts