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John McKenzie · 17 August 2009, 05:00 AM

Hi Joe , Bit of a " round about " posting , but hope it will be of some use .
1) Firstly , Sopwith 1 1/2 strutters were made in france and included the manufacturer " Hanriot "...Many were built , but cant help with # details
2)After early 1918 the 1 1/2 was generaly withdrawn from service (French) and saw widespread usage in flying schools as trainers .
3) On the web link you posted , ref. "Avions utilises....."Aeroplanes used by the gunnery school at Cazeau/seaplane section :"...There is a listing of the machines used ( Just above the 2nd RED heading of "Entrainement au tir aerien a Cazaux"....This listing says..(5th. down )."Sopwith 1A2 with Hanriot floats ( converted to seaplane ) (4)".....This note (4) underneath says .."convertion realised (made ) at the school ( number unknown) "
4) From the photos , the floats look like the later (2nd) type of float used on the Hanriot HD-2.(Earlier type was shorter and more like Sop.Baby type )..
These floats , being longer (at the rear ) allowed the aircraft to sit more tail high in the water than previously , and had a definate step .
5) Good photo of HD-2 ..No 241 with these floats is Imp War Museum photo #Q66288
6) US Navy took delivery of 10 HD-2 machines and took them back to the US Naval Aircraft Factory at League Island, Philadelphia, for conversion to land planes....(sometime mistakenly believed to have been built by N.A.F. )..
These given US Navy numbers A5620--A5629 & given Clerget motors .
7) It may be that some photos /Drawings or even parts of these floats may still exist...Who knows ?.....They are of course the same type that you would be looking for to replicate the French "school" 1 1/2 's at Cazaux .
8) US Navy did purchase also some 1 1/2 's.......Whether any of these machines ever met up with the above (ex) HD-2 floats is anyones guess....? But it "could" be...ie. Sop. 1 1/2 on HD-2 floats in US Navy markings ! ?
9) IMPORTANT..When the HD-1 was converted to 1st vertion (Sop Baby type floats ) to a seaplane , it was necessary to extend the Rudder and to add an under fin...Later , with the revision to the longer HD-2 (later version as per #241..It was found necessary to revise the whole shape of the vertical surfaces and a new combined upper and lower fins/ rudder assembly was used ..All this due to the increased side area of the floats as replacing the wheels .
10) From above , it is possible that the standard Sop. 1 1/2 Strutter Fin / Rudder combination may be inadequate as a Seaplane ...I cannot say if the "school" machines have been altered ( as I'm not Sop. expert ,just to look at it ) , or indeed if they were after the photo was taken , or IF they needed alteration at all ...You'd have to explore this one on safe handling grounds .
Hope some of this is of help or interest...

..Regards John.

17 August 2009, 05:00 AM	#673 (permalink)
John McKenzie Forum Ace Join Date: Oct 2008 Location: Southampton U.K. Posts: 1,789	Hi Joe , Bit of a " round about " posting , but hope it will be of some use . 1) Firstly , Sopwith 1 1/2 strutters were made in france and included the manufacturer " Hanriot "...Many were built , but cant help with # details 2)After early 1918 the 1 1/2 was generaly withdrawn from service (French) and saw widespread usage in flying schools as trainers . 3) On the web link you posted , ref. "Avions utilises....."Aeroplanes used by the gunnery school at Cazeau/seaplane section :"...There is a listing of the machines used ( Just above the 2nd RED heading of "Entrainement au tir aerien a Cazaux"....This listing says..(5th. down )."Sopwith 1A2 with Hanriot floats ( converted to seaplane ) (4)".....This note (4) underneath says .."convertion realised (made ) at the school ( number unknown) " 4) From the photos , the floats look like the later (2nd) type of float used on the Hanriot HD-2.(Earlier type was shorter and more like Sop.Baby type ).. These floats , being longer (at the rear ) allowed the aircraft to sit more tail high in the water than previously , and had a definate step . 5) Good photo of HD-2 ..No 241 with these floats is Imp War Museum photo #Q66288 6) US Navy took delivery of 10 HD-2 machines and took them back to the US Naval Aircraft Factory at League Island, Philadelphia, for conversion to land planes....(sometime mistakenly believed to have been built by N.A.F. ).. These given US Navy numbers A5620--A5629 & given Clerget motors . 7) It may be that some photos /Drawings or even parts of these floats may still exist...Who knows ?.....They are of course the same type that you would be looking for to replicate the French "school" 1 1/2 's at Cazaux . 8) US Navy did purchase also some 1 1/2 's.......Whether any of these machines ever met up with the above (ex) HD-2 floats is anyones guess....? But it "could" be...ie. Sop. 1 1/2 on HD-2 floats in US Navy markings ! ? 9) IMPORTANT..When the HD-1 was converted to 1st vertion (Sop Baby type floats ) to a seaplane , it was necessary to extend the Rudder and to add an under fin...Later , with the revision to the longer HD-2 (later version as per #241..It was found necessary to revise the whole shape of the vertical surfaces and a new combined upper and lower fins/ rudder assembly was used ..All this due to the increased side area of the floats as replacing the wheels . 10) From above , it is possible that the standard Sop. 1 1/2 Strutter Fin / Rudder combination may be inadequate as a Seaplane ...I cannot say if the "school" machines have been altered ( as I'm not Sop. expert ,just to look at it ) , or indeed if they were after the photo was taken , or IF they needed alteration at all ...You'd have to explore this one on safe handling grounds . Hope some of this is of help or interest.....Regards John.