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Target Tug Mechanism


Shark444

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Does anyone have any drawings or reference photos of the target tug mechanism fitted to Lysander, Fairey Battle, Northrop A-17 Nomad, or Bristol (Fairchild) Bolingbroke?  I can only find distance photos of these and you can't see much (if any) of the bracket.  I also know there was usually a wind turbine that may have helped to power the winch to let out the target drogue, but no shots on where/if that was fitted to the aircraft above.

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These aircraft (except perhaps the Bolingbroke?) had a pylon on the side of the fuselage below the aft crew position, which (from memory) appears to have a conical shape, wide at the base.  The wind turbine was mounted on a rotating top that could be turned into or out of the slipstream.  I think that there may be plans of this in the 4+ booklet on the Lysander.  You might be better looking for it in photos of the Martinet, which would rarely be seen without it.  It can also be seen on the Roc and Skua, and no doubt others.

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It seems to me the windmill was stowed horizontally and was built to pivot vertically for use.  Am I right in thinking the drag from the target sleeve was enough to deploy it and that the winch was used to haul the cable back in?  

 

 

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Some Bolingbroke intel from Carl Vincent:

 

The great majority of RCAF WW II Target Towing aircraft were equipped with an internal winch powered by an electric motor. A few of the earlier or more basic aircraft did have the wind-driven winch e.g. some of the Shark TT’s.

As one of my current areas of research and writing involves the Bolingbroke, I will deal solely with this aircraft although the installation was basically the same in the other types.

I attach the following images:

1 & 2.  The Test & Development Establishment report on the first trial of the equipment on the Bolingbroke. To the best of my knowledge this was adopted comparatively unaltered and so installed.

3.  An interior photograph of the cable reel, one of 13 detailed photos from the file.

4 & 5.  Two photos of the early installation of this equipment on a Bolingbroke at Patricia Bay.

6.  A photo of a Bolingbroke IV TT in service which gives us a profile view of the deployment chute.

 

I trust that this will be of use or, at least, of some interest.

 

  Carl

 

 

 

50188642993_1bd8a25fb4_b.jpg

 

50188643033_ddd96e43ca_b.jpg

 

50189444997_322f6e4d01_b.jpg

 

50189445037_a75eb8b448_b.jpg

 

50189191966_a75606477b_b.jpg

 

50189445112_269f04c6e6_b.jpg

 

 

 

 

 

Chris, for Carl

 

 

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15 minutes ago, dogsbody said:

Some Bolingbroke intel from Carl Vincent:

 

The great majority of RCAF WW II Target Towing aircraft were equipped with an internal winch powered by an electric motor. A few of the earlier or more basic aircraft did have the wind-driven winch e.g. some of the Shark TT’s.

As one of my current areas of research and writing involves the Bolingbroke, I will deal solely with this aircraft although the installation was basically the same in the other types.

I attach the following images:

1 & 2.  The Test & Development Establishment report on the first trial of the equipment on the Bolingbroke. To the best of my knowledge this was adopted comparatively unaltered and so installed.

3.  An interior photograph of the cable reel, one of 13 detailed photos from the file.

4 & 5.  Two photos of the early installation of this equipment on a Bolingbroke at Patricia Bay.

6.  A photo of a Bolingbroke IV TT in service which gives us a profile view of the deployment chute.

 

I trust that this will be of use or, at least, of some interest.

 

  Carl

 

 

 

50188642993_1bd8a25fb4_b.jpg

 

50188643033_ddd96e43ca_b.jpg

 

50189444997_322f6e4d01_b.jpg

 

50189445037_a75eb8b448_b.jpg

 

50189191966_a75606477b_b.jpg

 

50189445112_269f04c6e6_b.jpg

 

 

 

 

 

Chris, for Carl

 

 

WHEE...!   The lower strut and bracing of the tailplane is something I didn't know about.  I have an image of a 5OTU Boly awaiting disposal at Pat Bay in 1946 - now what I know what to look for, I can just make out the wire.  Also, it appears that the aircraft did not have any roundels on the wings; I'm wondering if they were painted over when the black diagonal striping was applied for the target tug livery and never re-applied.  Doesn't look to be any on the underside of the photo above, either, just the underwing serials.

 

Thanks, Chris!

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Hello all,

 

not exactly what the original poster wanted, but here are a few photos of a scratch built winch I made for my 1/48 scale SAAB B17A. According to the original Finnish Air Force documents the winch was of type "Mark MIIB" (I suspect that there is something wrong with the spelling, but can't be sure). The winch was originally mounted in a Miles Martinet target tug. This aircraft was originally operated by a Swedish company Svensk Flygtjänst AB and based at Gothenburg. SFT modified the winch (enhanced brake and smaller propeller for the windmill) and assembled it then into this SAAB. The aircraft was sold to Finland in 1959.

 

I could find only a couple of rather poor quality photos of the winch online, so it isn't extremely accurate.

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An original good quality colour photo shows an overall green colour that most likely was British "Eau de Nil". Note that in the photo above the colour is badly distorted. I mixed the paint using Hurricane Mk.1 interior colour as a reference (we have one example in original paint here in Finland).

 

Here are the bulges on both sides of the fuselage and the windmill arm.

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Note the propeller in its cruising attitude. As said earlier the armourer manning the rear seat threw the target sleeve out of the belly hatch and the drag pulled the cable out. The windmill was used at this point for slowing the target down. That hand cranck visible in the first photo was used to set a correct RPM for the windmill. Normally cables between 800 and 1200 meters in length were used. After the shooting the windmill provided power for reeling the cable back in. It took around one minute to reel back in 800 meters of cable. Before landing the target sleeve had to be jettisoned by a mechanical "guillotine".

 

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These two photos show the cable outlet and a guide rail under the rear fuselage.

 

Hope these help.

 

Cheers,

Antti

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In response to Shark444’s comments.

The RCAF’s Battle, Bolingbroke, Lysander and Nomad target tugs normally were fitted with guard wires around the tailplane. This is something that modellers should keep in mind.

All Bolingbroke TT photos in my collection that show the underwing have roundels in the conventional position. Unfortunately, I have none that show the appropriate area of the upper wing. However the other TT types all have them and, as the roundel position is on the original yellow, it seems probable that they would have been carried on most Bolingbroke TT’s.

Incidentally, I am not certain that the Perspex hatch replacing the lower escape door referred to in the T & D E report was actually fitted in service. One of the interior photos on the report shows the rails but not the hatch.

Carl

 

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The winch type B was the most common wartime version. The  drogue when released, pulled out the cable which was de-clutched from the windmill by a cam when the mill was at the lowest angle of attack, ie horizontal. The cable run-out was controlled by the angle of the windmill to the airstream via the clutch and a drum brake so the cable could be brought to a controlled stop (either way).

 

The target drogue was drawn in by rotating the windmill from the horizontal to the vertical (fully into the slipstream). The angle of the windmill blades to the slipstream controlled the speed in which the cable was drawn in by varying the the axis angle of the windmill by the combined clutch and speed control. The clutch was operated by a cam on the windmill pivot so that the speed of the cable return was variable up to a point when the clutch ceased to drive the cable drum The operator had a rev counter dial and he could monitor the cable length with a calculated placard and a counter.

 

John

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Ossington, that looks like a photo that would have been extremely useful for me a few months ago... It clearly says "Type B Mark II winch" (FINAF document says "Mark MIIB" winch; had to mean the same gear). Thank you for sharing those photos🙂

 

I'm happy with my winch as it looks close enough (if not accurate in measurements).

 

Cheers,

Antti

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