Centurion Breech Closing Speed
 

Hi, the closing speed of the breech on our Centurion seems slow. Yet everything is clean, lubed, and operating freely. Seems like closing spring is weak.
Link is

https://youtu.be/6indMWNCXBI

Seems reasonable to me, though I wouldn't close it by hand in that way....
17 pdr seems similarly slow compared to 6 pdr and especially 2 pdr but when you think about the block weight and hence inertia, it makes sense.

I’m not familiar with gunnery. Isn’t it the breech’s job to push the shell hard into the block to seal it? This breech action is so half-hearted, it seems it might stall half-way closed.
Malcolm

First off, think safety, the person depressing the ejectors has to many hands and fingers jammed up the breech ring, making a "chicken bar" based on the Leopard tank tool is easy to fabricate even making one out of plywood would do. As for "closing speed" it looks just fine (based on what I have seen on the Leopard) as others have noted you are moving a 115+ Lbs block of steel from dead stopped to closed so its hardly lightning fast. The correct way to close the breech from the open is grasp the breech opening lever with the left hand (reaching under right arm), depress the catch on the top with the thumb of left hand pull breech opening lever back enough to disengage contact with the ejectors, reach into the breech ring with right hand using the right hand thumb and pinky finger to trip the ejectors, KEEP the middle three fingers closed into palm (think the look of a Hawiiian wave) so you DO NOT see them chopped off by the closing breech (RIP Tooner Martin) , done right (and safely) the closing breech will brush the right hand away. I strongly suggest you discontinue closing the breech in the manner shown in the video.

What model of Centurion is this please ?

Cheers

Tim

No difference
 

Tim,

The mark of tank would not make a difference in this case. The Gun, 105-mm Tank L7A1 and the Ordnance QF 20-pdr Tank Mk.1 use the same breech ring and breech block, so the mechanism is common through all Marks of Centurion from Mk.3 to Mk.13. (Mk.1 & 2 used a 17-pdr.). I vaguely remember that this tank is a Mk.5 or Mk.5/2, but Malcolm will know for sure.

Mike

Tim,
As Mike will remember, there’s a long thread about the mark of this Cent on this forum. It’s a Canadian Mk 5/2, but that bears no comparison to the British mark numbering. It’s actually closer to a Mk 11.
The gun mounted is non-standard for either of those marks, it’s a 20 lbr, probably retrofitted later in its life to replace a 105.
Malcolm

Mike

My question was not related to the breech closing speed.

I am more interested in what model of Loader Safety switch is fitted on this variant and how that operates.

As you correctly point out Mk1 and 2 used the 17pdr - the functionality of which is very similar to the 17pdr Mk4 and Mk7 found on the firefly... which is where my interest is.

Cheers

Tim

https://m.youtube.com/watch?v=Yqfb8PzPAfc Have a look here at around 15:50 and 20:30

Excellent footage, Niels, thanks for posting it. Unusual to see such long and clear internal footage of loading, etc.

Tim, the thread was about the breech closing speed, so that's what I thought you must have been thinking of with your question about Mark.

The Cent Mks 3 to 11 equipped with 20-pdr or 105-mm guns fire electrically-primed ammunition and use an electrical firing circuit with a break switch that is opened as the gun recoils, and closed manually by the loader once the round is loaded. You can see the loader in the Youtube video per Niels link, throwing the switch lever after each round is loaded. The switch has a GEC manufacturing prefix, so I assume General Electric.

Mike