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Identify wooden 2 bladed propeller

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  • Identify wooden 2 bladed propeller

    I am an ex-RAAF engineer working at the restoration division of the Fighterworld Aviation Heritage Centre at RAAF Base Williamtown NSW Australia.
    We are in possession of a three laminated wooden propeller with the decal of "The British and Colonial Aeroplane Company Ltd Bristol Eng embossed on the blade. The only identification markings are the "D" 2600 and "P"1320 embossed on the side of the hub/boss.

    In addition we have contacted Bristol/BAes but they cannot help us under their GDP regulations. Strange?

    In most cases my research has led me to possibly the Bristol Boxkite "push" propeller but the 3 laminations are questionable seeing that most props of that era were 6 laminations especially the "pull" props regarding strength and durability. This could have maybe been an earlier prototype.

    The blades were partly coated and badly eroded with what looks like the old animal hide technique and many splits at the tips indicating possible ground impact. There are also pin hole indications of possible leading edge metal (brass?) protection sheathing that has been removed. We know through research that many propellers were made in England from Maple; Spruce etc, prior to and during WW1 to support aircraft manufacturing in Europe, possibly explaining why metric sizing was embossed instead of imperial, but still cannot identify the propellers origin.

    During 1912, Sir George White, the founder of The British and Colonial Aeroplane Company, sent 2 Bristol Boxkites to Australia on a promotional tour of Western Australia, Victoria and New South Wales. Both aeroplanes were finally bought privately by a Doctor in N.S.W. but the Australian Government purchased 4 for the Australian Flying Corp (AFC) that supported training pilots up too and throughout WW1. This gives us cause to believe a possible connection but we cannot speculate as a definite at this time.

    We at Fighterwold request any help we can get from this international forum, to pinpoint its post manufactured use and any history associated with it, whether it be a Boxkite or other type of aeroplane.

    I have attached some photographs in support.
    Attached Files
    Last edited by Simo; 12-09-2020, 08:31 PM.

  • #2
    The left hand rotation is often associated with a pusher application. The height of the hub suggests that it may have been stacked with another prop of identical height to create a 4-blade combination.

    Without a referenceable drawing number it's nearly impossible to know what make and model it was designed for. There were hundreds of different model props made before and during WW1.

    I'm not sure what's going on with the hub, but it certainly looks like it was carved out for a clock, barometer, etc. But is that an additional hole bored in the hub? That can also be associated with stacking two blades together.

    Attached Files

    Comment


    • #3
      Hi,

      It is an extremely old prop (1908 > 1914) made to be fitted between the plane and a 7 cylinders rotative Gnome engine.
      These props have 7 bolts holes and the central bore was 14 cm (5"1/2) and 4.6 cm (1 13/16) hub thickness.
      I will come back with a scheme of this very special fitting like the Chauvière prop on the plane of the joined pic.

      EDIT: The 50 HP 7 cylinders Gnome instruction manual shows two possibilities with the prop outside the engine or between the engine and the plane (see joined pics).
      The prop metallic hub was inside the prop, as shown on a picture of a Chauvière (see pic). The metallic hub has two grooves: I don't know if there are splines (right word?) or grooves and keeways on the shaft.

      Regards,
      PM
      Attached Files
      Last edited by pmdec; 12-10-2020, 04:58 PM.

      Comment


      • #4
        Hi pmdec & Dbahnson,
        It indeed has a seventh hole in the hub.
        I will go back to the museum today and measure up the bore, thickness etc and have info ready tonight for you both.
        Interesting that the chamfer would be possibly for ease of centering the prop during installation as well as the 3 rebated bolt holes, if the Gnome has corresponding lugs.
        Thanks for your immediate response.
        Regards
        Simo

        Comment


        • #5
          Does the arrow in the photo a few posts above point to an eighth hole? I can't tell whether that's a blemish or a drilled hole.

          Comment


          • #6
            you are right.

            There are indeed eight 10 mm diameter holes in the Hub mounting flange.
            I sought of dismissed anything but 6 x 178mm PCD diameter as the holes were not in a balanced configuration thinking torqueing and balance of the propeller might be an issue, however having looked at the standard Hubs of that era, they seem to be an eight holed alignment.

            The External Hub thickness is 70mm thick,
            The PCD of the hub mounting flange is 160mm diameter,
            The internal diameter of the hub mounting flange is 178mm,
            The internal thickness of the hub wood in the supposed bore is 40mm and
            The diameter of the above bore that accommodates a supposed prop metallic hub (ref pmdec) is 135mm diameter.
            Attached Files

            Comment


            • #7
              Hi,

              To be sure about measures, could you write them for each letter (A and C are "external", B and D, "internal")?

              About the bolt holes, could you confirm that the 8th hole is different from the 7 "regularly spaced" ones?

              Regards,
              PM

              Edit: Typo corrected
              Attached Files
              Last edited by pmdec; 12-11-2020, 09:19 PM.

              Comment


              • #8
                Hi,

                I have found in my database another prop designed to be fitted between a Gnome engine and the plane. It is a Rapid serial J, diameter 2550 mm, pitch 1500 mm (so not far from your 2600 / 1320).
                The blade width is 23 cm, hub total thickness 70 mm, internal bore 140 mm, and seven 8 mm holes on a 165 mm circle.
                This Rapid serial J is from 1912, but the ones made in 1910 had a 1350 mm pitch.
                From Ratier archives, those serial J were left hand pushers made for Farman and Sommer biplanes fitted with 50HP Gnome Omega.

                Regards,
                PM
                Attached Files

                Comment


                • #9
                  Hi PM,
                  Dimension A = 70mm
                  Dimension B = 40mm
                  Dimension C = 178mm approximate Diameter
                  Dimension = 135mm approximate Diameter
                  Regards the holes, it is possible that they were 8mm in diameter and the PCD could be around 160 to 165 diameter based on the state of this propeller.
                  I will check the chord width of the paddle blade next Tuesday at the Museum.

                  Thanks again for this excellent research.

                  I read that Henry Farman developed the Farman 1,11.111 that was design copied by Sir George White for the Bristol Boxkite and others around 1909.

                  Is it possible that he acquired the decal from The British and Colonial Aeroplane Co Ltd and stuck it on the blade along with metric embossed D and P. Food for thought.

                  Regards
                  David (Simo)
                  Last edited by Simo; 12-11-2020, 10:52 PM.

                  Comment


                  • #10
                    Hi,

                    Thank you for the measures. If you can't get a precise number for the PCD, you can precisely measure the distance between two bolt hole centers: If the PCD is 165 mm, the distance between two adjacent bolt hole centers have to be 0.434 x 165 that is 71.6 mm (see joined pic).

                    About the British and Colonial decal, I don't think it was acquired: B&C probably made the prop (with their decal(s)), perhaps copying one of the French props used on planes fitted with a 50HP Gnome Omega and the pusher prop between the engine and the plane). I know the measures for three of them:
                    - Chauvière serial 2212-1 (D=2600, P=1600, BW=250)
                    - Rapid serial J (D=2600, P=1350, BW=? in 1910, D=2550, P=1550, BW=250 in 1912)
                    - Rapid serial K (D=2600, P=1450, BW=? in 1910, D=2600, P=1300 to 1450, BW=260 in 1912).

                    For the Chauvière 2212-1, the given measures are the ones approved in 1916. I am waiting (from somebody who has the one pictured on my 12-10-2020 08:57 PM post) the true measures (perhaps by next week-end) for the one pictured because it is earlier (it has the prop number 9??2, therefore made in or before 1914).

                    Regards,
                    PM

                    Edit: wording after "week-end)."
                    Attached Files
                    Last edited by pmdec; 12-12-2020, 03:53 PM.

                    Comment


                    • #11
                      Sorry for the delay PM but I have been in Covid 19 Lockdown not being able to travel to the museum.
                      Also I was scammed today and had to clean it up before sending you the values.
                      Please keep in mind that these values attached are estimates considering the damage done to the propeller.
                      Regards
                      Simo
                      Attached Files
                      Last edited by Simo; 12-22-2020, 04:23 AM. Reason: Left out attachment

                      Comment


                      • #12
                        Hi,

                        Thank you for the PDF. I have some measures from the owner of the 2212-1 Chauvière pusher used on a Gnome Omega and fitted between the engine and the plane: see pics. I have added what I think is how the metallic hub is made.

                        Best regards,
                        PM
                        Attached Files

                        Comment

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