Propeller I.D.

[bauple58]

The RAF's 618 Squadron, equipped with Mk.VI Mosquitos, was based at Narromine (New South Wales) between January and July 1945. These planes had been modified for 'Highball' operations, and were fitted with four-blade propellers. The Narromine Aviation Museum has been offered a propeller (pictured) which is allegedly from one of these 618 Squadron aircraft. Before proceeding to purchase however they want to ascertain if the unit being offered isn't in fact from a Lincoln (which apparently looks very similar, albeit, with a 6" diameter variation).

Would anyone here have any technical data that might allow us to determine if this unit is indeed appropriate for a Mk.VI 'Highball' Mosquito which, we're led to understand, could accept both Rotol and DeHavilland propellers?

Thanks

 

[Crimea_River]

Welcome aboard. I have only skimmed through my references to get up to speed on this but at first glance, it seems that some of the background info may be getting mixed up a bit.

618 Squadron was indeed used to test Highball in 1943 but I believe that this was done with modified B. MkIVs with three bladed props. The initial hurry was to enable the new weapon to be used against the Tirpitz in May of 1943 but tests continued beyond this timeframe into 1944. In late 1944, 618 was sent to the Pacific to be a carrier-based anti-shipping unit. Its Mosquitoes now received the 4 bladed props, Merlin 25 engines and arrestor hooks but I don't know what version of Mosquito they used at this time, nor do I have a spec for the type of prop used. One reference says that they were Rotol props.

On a separate trajectory to the 618 history and early Highball trails, development of a naval Mosquito was started in 1944 using modified FB.VIs. Ultimately, the production Sea Mosquito carrying 4 bladed props would be known as the TR Mk. 33 and these began to come off the lines in late 1945 well after 618 Squadron had been disbanded. I have data that the second production TR Mk. 33. serial number TS449, had a deHavilland 12'-6" diameter propeller, Type D/14/445/2. Perhaps markings on your specimen can be found to match this number.

The TR Mk. 33 was used to test an improved version of the bouncing bomb, known as Highball 2 that was also envisioned for use with the Sea Hornet. These tests all occurred after WW2 and therefore independent of any 618 Squadron operations.

So, in summary, it's possible that the prop might a 4 blader from 618 when it was based at Narromine but 4 blade Mosquitoes also operated independently of 618 squadron.

Hope this helps.

 

[Tom Fey]

The propeller above is a Curtiss Electric: one piece hub ( so not Ham Stand Hydromatic), slip rings on the aft side of hub, hollow steel blades that will go "bong" instead of "tink" when you rap them. Sitting upside down flat on the ground like that likely means the electric motor and reduction gear assembly is missing from the center of the prop on the front of the hub. The propeller model number will be on the top edge of blade socket (barrel) #1. I'm not aware that any Mosquito used a Curtiss Electric propeller.

 

[bauple58]

Welcome aboard. I have only skimmed through my references to get up to speed on this but at first glance, it seems that some of the background info may be getting mixed up a bit.

618 Squadron was indeed used to test Highball in 1943 but I believe that this was done with modified B. MkIVs with three bladed props. The initial hurry was to enable the new weapon to be used against the Tirpitz in May of 1943 but tests continued beyond this timeframe into 1944. In late 1944, 618 was sent to the Pacific to be a carrier-based anti-shipping unit. Its Mosquitoes now received the 4 bladed props, Merlin 25 engines and arrestor hooks but I don't know what version of Mosquito they used at this time, nor do I have a spec for the type of prop used. One reference says that they were Rotol props.

On a separate trajectory to the 618 history and early Highball trails, development of a naval Mosquito was started in 1944 using modified FB.VIs. Ultimately, the production Sea Mosquito carrying 4 bladed props would be known as the TR Mk. 33 and these began to come off the lines in late 1945 well after 618 Squadron had been disbanded. I have data that the second production TR Mk. 33. serial number TS449, had a deHavilland 12'-6" diameter propeller, Type D/14/445/2. Perhaps markings on your specimen can be found to match this number.

The TR Mk. 33 was used to test an improved version of the bouncing bomb, known as Highball 2 that was also envisioned for use with the Sea Hornet. These tests all occurred after WW2 and therefore independent of any 618 Squadron operations.

So, in summary, it's possible that the prop might a 4 blader from 618 when it was based at Narromine but 4 blade Mosquitoes also operated independently of 618 squadron.

Hope this helps.

Thank CR for your prompt and considered remarks

 

[bauple58]

The propeller above is a Curtiss Electric: one piece hub ( so not Ham Stand Hydromatic), slip rings on the aft side of hub, hollow steel blades that will go "bong" instead of "tink" when you rap them. Sitting upside down flat on the ground like that likely means the electric motor and reduction gear assembly is missing from the center of the prop on the front of the hub. The propeller model number will be on the top edge of blade socket (barrel) #1. I'm not aware that any Mosquito used a Curtiss Electric propeller.

Tom

You're correct it is American, the owner having since advised it is from a Martin Mariner. He also reports the following stencil on one blade... "814-4C3".
Does this look to you like a Curtiss code?

Mark

_____________

The propeller above is a Curtiss Electric: one piece hub ( so not Ham Stand Hydromatic), slip rings on the aft side of hub, hollow steel blades that will go "bong" instead of "tink" when you rap them. Sitting upside down flat on the ground like that likely means the electric motor and reduction gear assembly is missing from the center of the prop on the front of the hub. The propeller model number will be on the top edge of blade socket (barrel) #1. I'm not aware that any Mosquito used a Curtiss Electric propeller.

 

[Tom Fey]

Mark, The Mariner used Curtiss 836 series propeller blades. According to TO-00-25-29, Curtiss 814 series blades were used on the Martin B-26.

 

[bauple58]

Mark, The Mariner used Curtiss 836 series propeller blades. According to TO-00-25-29, Curtiss 814 series blades were used on the Martin B-26.

Wow. Thanks again Tom... possible, but not expected. Mariners were scrapped nearby, and although Marauders were used in Australia they were uncommon in this particular region

 

[Tom Fey]

Wow. Thanks again Tom... possible, but not expected. Mariners were scrapped nearby, and although Marauders were used in Australia they were uncommon in this particular region

Glad to help. To be clear, I do not know what other aircraft may have used the 814 series Curtiss blade, but I can say the Martin B-26 did!