C-47 That's All-Brother flame dampeners, where they from??

[Frantish]

C-47A "That's All-Brother"equipment search challenge, origin of flame dampeners / suppressors

The one item on TA-B that is unknown by us is the Flame Dampeners (aka Suppressors), so I am asking across several boards (first with the English ones).

Looking at film of the aircraft it shows some kind of Flame Suppressors / Dampeners under the wings.
Since the para drops was at night it is obvious a necessity.

However the USAAF rarely did night missions so that device is somewhat unique.
It is my belief the USAAF went to RAF colleagues and "borrowed" some off a Halifax or Beaufighter.
I am asking this bunch of hanger bums to divulge what rumor they have and post here.

Video of That's All --- Brother is here, one can see the longer exhaust tubes as it takes off.

View: https://www.youtube.com/watch?v=IS5bKV9I4mo

Still of film (ignore yellow arrow, points to Radar dome. Instead look around gear struts):

It is not difficult to find C-47's with it installed, but the images tend to be grainy and being under the wing dark! Something with excellent detail is needed.

And a picture of another C-47 with suppressors.

Some existing RAF samples (I call them RASP Type because this reminds me of the wood tool).
Halifax

Beaufighter

On a side note:
QUESTION: does the RAF type also reduce engine exhaust noise??


On a side note , picture of crew was found with TA-B, but the suppressor was NOT installed at this time.

THANKS FOR HELPING!

 

[Greyman]

First glance reminds me of Wellington exhausts/flame dampers - can't say for sure though.

Flame dampers were fitted to Wellington IVs, which had Twin Wasp engines. Might be worth investigating.


For what it's worth I've heard 'RASP' dampers referred to as 'Barbed' or 'Christmas Tree' exhausts.

 

[Frantish]

First glance reminds me of Wellington exhausts/flame dampers - can't say for sure though.

Flame dampers were fitted to Wellington IVs, which had Twin Wasp engines. Might be worth investigating.


For what it's worth I've heard 'RASP' dampers referred to as 'Barbed' or 'Christmas Tree' exhausts.

Those alternate names are great to know!

I knew the Wellington had same engines, but images with those engines did not have the rasp ones, still did find this:

and on Sterling

 

[Greyman]

One thing to watch out for about those exhausts is that they are often asymmetric. Like in the image of the line up of C-47s, the starboard exhaust is the 'hedgehog' damper (another nickname I found), and the port is the longer, smoother piping.

EDIT: image added - same aircraft, I just zoomed in and cropped/spliced. Pegasus engines.

 

[Koopernic]

Why was there a need for flame dampers, we're they only required for when the aircraft was running a rich mixture, i.e. combustible fuel in the exhaust that could ignite on contact with air?

Also why did the aircraft loose speed: jet thrust, back pressure or drag?

It seems DC3 doing night drops of paratroopers needed both H2X and flame dampers

 

[Greyman]

Weak mixture settings still produce flames, in some cases more visible ones than rich mixture.

As for the specific causes for speed loss I'm not sure. But yeah, I would guess drag of the actual apparatus and lack of jet thrust.

 

[Wildcat]

You can add the CAC Boomerang to your list too, same engine as the C-47 as well.

 

[Frantish]

Weak mixture settings still produce flames, in some cases more visible ones than rich mixture.

As for the specific causes for speed loss I'm not sure. But yeah, I would guess drag of the actual apparatus and lack of jet thrust.

I think more back pressure as longer pipes reduce flow, then the dampener itself.
Thanks for all your input!

You can add the CAC Boomerang to your list too, same engine as the C-47 as well.

Thanks!

 

[Frantish]

phenomenal success in fund raising!

Unfortunately much less success in finding about those dampener!

 

[Frantish]

Believe it or now, we STILL unable to find anything about those flame dampeners!

Lots of pictures and stories of those involved with TA-B are pouring in, but nothing on the stack.

Anyone take a second look?

 

[Airframes]

I can only guess that, as the aircraft were based in the UK, that the dampers came from British sources. They were commonly know as 'Hedgehog' or 'Porcupine' exhausts, due to their 'prickly' appearance, and were fitted to most RAF radial-engined aircraft engaged in night operations.
Aircraft with in-line engines, such as the Lancaster, were fitted with a semi-circular profile 'shroud' covering the exhaust stubs to perform the same function.

 

[vikingBerserker]

I am with Terry on this one, I cannot find any made in the US in that style.

 

[dogsbody]

Yes, definitely a British design. The RAF started flying night missions early in the war after they realized their bombers were no match for Luftwaffe day fighters.


Chris