identité de cette Hélice Spitfire?

[Wurger]

The red dots are explained here: ROTOL Propeller Markings and Information

Andy, IMHO that's not the point. Our mate asked about the "red" dot seen in the pic above. I have enlarged this. See below.

The link you posted is about the Disk(s) actually identfying not the prop blade manufacturer but the meaterial it was made of. Usually there was some of the additional blade data info applied on the disk, eg.. the covering type, sheath kind. Also it was of different colour in order to indicate the balde structure. The requested dot is noting more but a small dot made of a pink ( IMHO) colour made by somebody with a brush and doesn't have anyting in common with the true disk painted on the balde. See below.

 

[Wurger]

So it would be a propeller made by JABLO and not ROTOL?

JABLO is not a firm but the name of the material the blade was made of. It is the jablo wood in the case. But the manufacturer's name is the Rotol.

 

[Wurger]

I can't get any answers from hercules propellers that have plans with dimensions.
I am looking for propeller blades for spitfire and seafire with dimensions.
To examine which models they might belong to.

Here the prop diameters .. from Morgan and Shacklady. Take the length of the blad and multiply by 2. Then convert it into the inches. Compare the result with the prop the data below. The closest result may be your Spitfire type.

VIII, IX, XIV 10 feet 9 inches
XII, XIX 10 feet 5 inches
XIV 10 feet 4 or 5 inches
F.24 11 feet 10 inches

 

[Tom Fey]

Some info on the 5 blade left hand Rotol propellers.

 

[Crimea_River]

JABLO is not a firm but the name of the material the blade was made of. It is the jablo wood in the case. But the manufacturer's name is the Rotol.

Jablo Propeller was a manufacturer based in Manchester and is also the material name.

Sorry for the confusion about the dot. I thought that the OP was seeing some remnants of the manufacturer disc.

 

[waroff]

. Take the length of the blad and multiply by 2. Then convert it into the inches.

and add the diameter hub?

 

[Wurger]

and add the diameter hub?

IMHO it can be omitted because the blade root is going quite deep into the hub. I would say, the diameter of the shaft that goes through the hub rather.

 

[Wurger]

Jablo Propeller was a manufacturer based in Manchester and is also the material name.

The Jablo Propeller Company also known as F.Hills & Sons is a different matter in that case. The scanned documents with the markings you posted reffer to the Jablo wood material and the covering type but not to the firm. However I agree that the JPC was one of the prop blade manufacturers.

 

[waroff]

I would say, the diameter of the shaft that goes through the hub rather.

yes that's my thought, but I have not the words to tell it

 

[Wurger]

Oh ... I see. So you are right. It should be added too. But I thought it might be omitted to make the measuring process easier .

 

[Crimea_River]

The Jablo Propeller Company also known as F.Hills & Sons is a different matter in that case. The scanned documents with the markings you posted reffer to the Jablo wood material and the covering type but not to the firm. However I agree that the JPC was one of the prop blade manufacturers.

OK but the documents say that a white disc is for Rotol Airscrews Ltd., a Yellow disc for Weybridge Blades, and a pale blue for Curtiss Blades. These are all manufacturers.

Anyway I will bow out of this discussion as I'm just confusing things.

 

[Tom Fey]

Depending on the prop shaft size and the design and manufacturer of the propeller / propeller blade / hub, there is approximately 6 inches of space between the bases of opposed blades when blades are secured in the hub. So approximate propeller diameter would be: (length of separate blade in inches + 3 inches) x 2. I can say for an Aeroproducts A422 E1, 2 blade propeller (40 spline prop shaft) the blades stand 57.375 inches tall and the installed diameter is 10 feet 0.5 inches diameter.

 

[Wurger]

OK but the documents say that a white disc is for Rotol Airscrews Ltd., a Yellow disc for Weybridge Blades, and a pale blue for Curtiss Blades. These are all manufacturers.

Anyway I will bow out of this discussion as I'm just confusing things.

It's fine Andy. Glad you joined thet discussion. I have seen the revised Dowty-Rotol service manual pages with the disks colours somewhere in the net , as memo serves. According to my notes, the Rotol Airscrews Ltd. used the Pink ( Red) disk for the Jablo wood. The Weybridge Blades ( The Airscrew Company Ltd. of Weybridge) used the yellow one because they made the blades of the spruce or douglas fir spliced into birch laminations at the root end "Jicwood"

 

[nuuumannn]

Great information being passed around here.

Out of information for the original poster, Rotol was a joint effort between Rolls-Royce and Bristol established before the outbreak of WW2.

 

[ThomasP]

Here is some info I have in my notes on Rotol props.

The Rotol colour code for the disc changed at some point post-war (1946?), but I am not sure exactly when.

The original Rotol disc colour code:

Wood

White____Rotol manufactured Jablo blades with Rotoloid covering
Pink_____F. Hills & Son manufactured Jablo blades with one of three coverings - either Jablo (covering), Venus, or Cristofin
Green___ Hordern-Richmond manufactured Hydulignum blades with one of two coverings - either Rotoloid or Cristofin
Yellow___Weybridge/Airscrew Company Ltd. manufactured Spruce blades with one of three coverings - either Rayoid, Schwarz, or Acetate

Metal

White____Rotol manufactured Aluminum blades
Lt. Blue__Curtiss manufactured Aluminum or Steel blades

The revised Rotol disc colour code:

Pink for Jablo blades with one of three coverings, either Rotoloid, Jablo (covering), or Cristofin
Green for Hydulignum blades with one of two coverings, either Rotoloid or Cristofin
Yellow for Spruce blades with one of three coverings, either Rotoloid, Schwarz, or Cristofin


Coverings

Rayoid is a cellulose nitrate thermoplastic. It was used in sheet form, heated and pressed onto the surface of the wood blade, with the Rayoid bonding to the surface of the wood.

Acetate (covering) is a cellulose acetate thermoplastic, cheaper to produce than the Rayoid cellulose nitrate thermoplastic, and more easily applied to wood. It can be applied either in sheet form by heating and pressing, or as a liquid paint when suitable solvents are used.

Cristofin (Crystaline finish) was a variant of Formvar™ (polyvinyl formal varnish), a synthetic resin made into a varnish. It was painted in multiple layers onto the wood surface of the blade and bonded to the wood surface. It dried hard and very clear.

Rotoloid was a combination of materials - a fine phosphor-bronze 'gauze' was wrapped around the wood blade, then Rayoid sheet was heated and pressed onto the surface under high pressure, the Rayoid flowing penetrating/permeating/encasing the phosphor-bronze 'gauze' and bonding to the wood surface. (Note: The info I have seems to indicate that sometime post-war, the meaning of Rotoloid covering became synonymous with simple Rayoid covering. The term Jablo covering, and the materials/process it describes below, then became the standard when including phosphor-bronze 'gauze'.)

Jablo (covering) was a combination of materials similar in structure to Rotoloid - a fine phosphor-bronze 'gauze' was wrapped around the wood blade, but then the blade was painted with a varnish similar to Cristofin (maybe actually Cristofin) which penetrated/permeated/encased the 'gauze' and bonded to the wood surface of the blade. Multiple layers of the varnish were applied to build up a smooth contour.

Schwarz covering was a layer of linen cloth wrapped around the blade with a cellulose acetate thermoplastic heated and pressed onto the surface of the cloth, with the plastic penetrating/permeating/encasing the cloth and bonding to the wood surface of the blade.

I do not have any information on the Venus covering other than it was a synthetic resin varnish that was brushed on in multiple layers to build up a smooth contour.

 

[Wurger]

So both Andy and I are right. Just two different periods of the time.

 

[53B]

Here are two other markings that are placed at the bottom of the propeller blade: I 0I 67 & 23 33.
Are these markings from the propeller blade design?

 

[53B]

Thank you very much to all of you for your fabulous explanations and especially to you Thomas P. So I have another question the traces we see are the traces of rotholoid? What were the coverings for you on this propeller blade?

 

[Wurger]

Here are two other markings that are placed at the bottom of the propeller blade: I 0I 67 & 23 33.
Are these markings from the propeller blade design?

It looks like the drawing number is 10167 (RA 10167) . If it is the RA 10167 the blade could be for Rotol R22/4F5/8 propeller which was fitted to Griffon VI engined Mk.XV and Mk. XVII Seafires.

 

[53B]

Thanks
So it would be a Seafire mkXV or mkXVII and the reference of this blade would be R22/4F5/8 at Rotol?
Is this the design number of the blade: I 0I 67 & 23 33?