unknown item related to Portugese armaments

[earni74]

Can anyone identify this item, all steel with adjustable parts, spiked on the base as if need to dig into ground to reduce movement,thanks

 

[Dreamk]

It looks rather similar to the support of torpedo launching visors of interwar naval aicraft. If the scale of the graduation on the base is in feet and not in meters, this iscompatible with the launching range and torpedo ranges of the period - objectives were mainly slow speed cargo ships and troop transports allowing a successive launch at such distance with torpedoes running at 30-40 knots. In the 1930s, the Portuguese operated 6 British-made Blackburn Shark Mk IIA in this role of torpedo bomber.

 

[earni74]

Interesting Dreamk, many thanks, i will try to find a picture

 

[Dreamk]

I must have somewhere a picture of the Levasseur PL-7b torpedo sight that may have been the inspiration of this Portuguese object.
The standard British torpedo sight was a much primitive one (even on the Barracuda of 1944) - a simple straight horizontal bar with light bulbs at regular intervals, and this may have pushed the Portugues to devlop their own version of a more "modern" and efficient torpedo sight.
The Levasseur was relatively more complex than the British sight (a simplified form of teh Levasseur was developped in Japan and became standard on the Japanese Navy's torpedo bombers, and similarly the Japanese copy of the STAe bombsight became standard equiment of the IJN's bombers, till the entry in service of a more modern copy of the Goertz 'automatic" bombsight). the Levasseur was coupled to a primitive (but quite advanced for teh period) mechanical computer, to enable its adaptation to various targets' speeds.
The US recognized early the need to develop a more advanced torpedo sight and their standard equipment in ww2 was definitively more advanced that their european parallels. However it is only near the end of ww2 that a really efficient torpedo sight was developped...when the aerial torpedo was becoming an obsolete weapon, at teh dawn of the era of rockets and missiles.
One must add that the real problem of torpedo bombers was not so much the torpedo sight as the exploder of the torpedo - the British and Italians had excellent hardware (copied by Russians and Germans) but the French exploder was widekly known for its infamous tendency to...spontaneously self-activate in mid air with the consequences one may expect. Therefore French crews used to fly with "locally inactivated" exploder through an arrangement of metal wire that held the prongs of the exploder, even in wartime. No operational torpedo launch was ever made by French torpedo bombers and the existing photographs show consistently exercise torpedoes (without the characteristic prongs of the real exploder). Even the celebrated Latecoere 298 was used operationally as a semi-dive bomber over land objectives.
The woes of the exploder of the US Mk13 torpedo are also well known - early versions demonstrating a deplorable tendency to explode at every angle of hit except around 90 degrees, so the better the aim the worst the result. This was already corrected by 1943, the other flaws of the Mk13 torpedo itself being then corrected in 1944-45.

Having said all this, there is yet no proof that teh bove object is indeed a torpedo sight.

 

[Draoich]

Hi earni74,
I have no knowledge of torpedoes, aerial or otherwise, but it seems to me that the azimuth graduations are in mils (6400 mils in a circle) and the top item is definitely a clamp for a tube so perhaps for a telescope?

Regards,

Draoich

 

[earni74]

Thanks Draoich, i will get to the bottom of it eventually and post result on here
Mick