Questions - late+postWW2 Bofors AA gun development in UK

[hammy]

Hi gang ,
can someone expound / direct me to sources on this subject please ?
I know about the basic single , twin and doubled twins=quads , and that the barrel lengths increased fro 50 to 60 and more recently to 70 calibres , and I've viewed the USN Gun instruction videos over on U-Tube .

Specifically , what was a Hazemeyer mounting , and how does it differ from the standard ?

What was the Bofors "Boffin" gun ?

Was there a 6 barreled mount developed ( I think fitted to the post-war Ark Royal and Eagle CVs ) with the barrels in two rows of three ? What was the ammo feed system then ?

[Byron Angel]

Hi gang ,
can someone expound / direct me to sources on this subject please ?

..... Friedman's recent book on British destroyers and frigates. There is also a variety of material (good, bad, and indifferent - as usual) on the web - just google "hazemeyer bofors" or "hazemeyer mount". IMO the best single website is probably here - http://www.navweaps.com/Weapons/WNUS_4cm-56_mk12.htm

Specifically , what was a Hazemeyer mounting , and how does it differ from the standard ?

..... The "Hazemeyer" mount was a a product of pre-war German Siemens-Halske technology (S-H actually controlled the nominally Dutch Hazemeyer firm). It was essentially a stabilized gun mount with its own range-finding apparatus and on-mount fire predicting (tachymetric) computer which automatically computed and applied lead corrections to the sights. Triaxial (roll, pitch, and yaw) stabilization provided a level reference platform for the fire control computer. IIUC, the original model required two separate sets of crewmen to control the gun: one team acting as gunlayer and trainer to keep the gun sights centered upon the target, and a second team manually managing the stabilization. I believe that later wartime modifications automated the mount stabilization function and added on-mount radar-ranging. It was this stabilization function that distinguished it from other AA mountings of the day.

Testimony to its value lies in the fact that the RN stayed with it throughout the war in one fashion or another, but the technology was subject to criticism on grounds of excessive weight and complexity, and difficulty of maintenance (especially as regarded the on-mount radar).

What was the Bofors "Boffin" gun ?

..... The Bofors "Boffin" was a single Bofors 40mm gun mounted upon the twin-20mm Oerlikon hydraulically powered mount.

Was there a 6 barreled mount developed ( I think fitted to the post-war Ark Royal and Eagle CVs ) with the barrels in two rows of three ? What was the ammo feed system then ?

..... Can't help on this.



Merry Christmas,

Byron

[hammy]

Thanks very much Byron , thats an EXCELLENT resource , and a nice Christmas present which has made everything clear to me !

That 6 Barrelled mount is in there as a brief mention in the text , and if you look at the pictures , and at the end click on More Pics , and at the end of that click on Bofors , you get into the Vickers engineering + shipbuilding photo archive where there are about a dozen or more good views of the mount .

Looking at those , the ammo feed is from flat trays of 36 rounds , and the barrels arranged in two vertical rows of three , the uppermost pair close together and set back , the middle ones wider apart and pushed right forward , and the lower ones at the same wide spacing , but pulled back halfway between the ones above and the ones above that , so you get open access to each side's set of three loading trays , and at all elevation angles .
Very clever layout .
The Gunner gets his own little box to sit in , on the left looking forward in the direction the barrels are pointing , and he's got a perspex "fishtank" to keep his head dry .

[Byron Angel]

Thanks very much Byron , thats an EXCELLENT resource , and a nice Christmas present which has made everything clear to me !

That 6 Barrelled mount is in there as a brief mention in the text , and if you look at the pictures , and at the end click on More Pics , and at the end of that click on Bofors , you get into the Vickers engineering + shipbuilding photo archive where there are about a dozen or more good views of the mount .

Looking at those , the ammo feed is from flat trays of 36 rounds , and the barrels arranged in two vertical rows of three , the uppermost pair close together and set back , the middle ones wider apart and pushed right forward , and the lower ones at the same wide spacing , but pulled back halfway between the ones above and the ones above that , so you get open access to each side's set of three loading trays , and at all elevation angles .
Very clever layout .
The Gunner gets his own little box to sit in , on the left looking forward in the direction the barrels are pointing , and he's got a perspex "fishtank" to keep his head dry .

..... You're very welcome; Navweaps is a well managed and pretty reliable site - one of my listed favorites.

Thanks also for your photo tip, BTW. First time I've ever viewed images of a Bofors 40mm 6-gun mount.


Byron

[hammy]

Good Demonstration of why it is good idea to put the aiming away from the mount in a seperate director -- I should think the Gas blast in front of the mount would have made ongoing accurate optical sighting pretty problematic !

[ontheslipway]

Mroe pics here

[hammy]

Thanks for putting those up foeth .

I'd love to have done it but as I am a complete " Boneheaded Klutz " at I T stuff , I wouldnt have a clue how to ( I cant even work those Smily things next door ! )

Thanks to your good work we've also now got the whole Vickers Photo Archive on there too which has about a zillion crisp photos of ships and their components of direct relevance to the majority of posts on most of the Bismark forums .

1 x Bismark Forum Medal for Outstanding Contribution is in the post to you !

Happy New Year Boys + Girls .