Hurricane Mk.Is – choice of propeller?

I quite agree with the neglected/confused parts of the Hurricane’s history. So many of the numerous books just repeat and re-package what has gone before. As for the Hurricane equivalent of “Spitfire, the History”? Yes, Martin Goodman has been working on the history of all the Hurricanes for the last few decades and intends to produce a series of volumes (grouping the various production batches to even out the volume size) giving the history of each airframe, complete with photos where available. Should fill a gap in many a reference book collection.

As a ex-Durham lad and keen modeller, I do indeed have a specific interest in 607 Sq. However, more generally the Hurricane is also a specific interest, and I do feel that some parts of its history are neglected, or even confused, in even the best works on the subject. I recall something on this forum about a Hurricane equivalent of “Spitfire The History” being prepared – do you know any more about this?

From photographic evidence I have the Gloster changeover as being at the end of the P26s and the start of the P27s, but no specific individual airframe number. Thus I think you are quite safe with 607 having DH unless your numbers get very close to the end of the P26s. Do you have a specific interest in 607?
Once you are into the P27s all have Rotol, as does the Hawker batch starting P32 (21.2.40) which agrees well with Edgar Brooks evidence. Then the exceptions occur e.g. in the third Hawker batch, up to P3708 and after P3762 have Rotol, but P3731 and P3733 both have DH (I don’t know how extensive this DH sub group is). These two aircraft went to ME and hence my thoughts about DH being the preferred fit for ME destined aircraft at that time, probably based on the harsh operating environment there – the DH having alloy blades and the Rotol being wood.

http://www.britmodeller.com/forums/index.php?/topic/234939547-which-hurricane-mkis-had-which-props/

Edgar was good enough to show the document rather than just quoting from it.

An alternative reason for the ME to have DH props could be simply standardising on the first one they received. Just theorising, but if Rotol had entirely replaced DH on the production line then there has to be a reason why the ones for the ME had DH props at all. This isn’t an area I was expecting to crop up – my specific interest beyond the general historic was the aircraft delivered to 607 Sq in France. As being in the P25xx and P26xx ranges, these would appear to have been built before the introduction of the Rotol.

Graham,
By ‘mix’ I meant that the start of the batch was with DH but at some point the production line changed to Rotol. (Edgar Brooks date looks to be in the right area – is there a source for that?) However the occasional aircraft from that batch, and the third Hawker batch, are seen in photographs with DH props, usually in a Middle East scenario, and hence my additional comment.

Mason’s early works were ‘landmark’ for their time, but ‘typos’ and errors did creep into the later revamped and enlarged Hurricane book.

ME DH props – it is merely an observation from photos. If the observation is correct, I would guess it might be related to wear in the harsh dusty environment. Likewise, I have seen no such statement.

Agree with your suggestion about the Hawker second and third batches – probably very early into the third batch, or even the start, but I have no documentary evidence for it.

Thank you Mike and Foray. Your comments have helped reduce the size of the problem.

Foray: when you say that the first Gloster batch had a mix of DH and Rotol, do you mean to imply that all later ones only had Rotol? This would link to the date Mike gives. Mason quotes the first batch from 12/39 to 4/40, the second from 7/40 to 8/40, and the third from 7/40 to 11/40. I suspect the dates for the second batch are wrong, as there should be no gap in production. Thanks to Edgar Brooks on Britmodeler, I’ve seen a document stating that production will have Rotol propellers from late February or early March (“a few weeks” after 7/2/40). This document also states that Rotol props would not be retrofitted to existing aircraft but only supplied to newbuild.

I don’t know any reason why DH props would have been favoured in the ME, and don’t recall seeing any such statement. That doesn’t mean you’re wrong. Photos certainly do show DH props, though I don’t know that all do. Is this another example of keeping the best “on the island”?

Mike: This suggests that Hawkers will have delivered the end of the second batch with DH props, and that Rotol were introduced early into their third batch (which is dated 21/2/40 to 20/7/40). What isn’t clear is whether they were initially fed into both lines on an “as available” basis, with the Rotols steadily fitted to larger proportions of the production, or whether there was a single specific “switch-over” for each (or either) line.

A Ministry of Aircraft Production memo dated 29th June 1940 noted “…the Hurricane I aircraft now being delivered from the manufacturers all have Rotol constant speed airscrews” and that “…the De Havilland two-pitch airscrews on Hurricane I aircraft are due to be modified when Spitfire I aircraft have been completed” ( Air 2/2822). Operations Record Books note delivery of Rotol/constant speed propeller equipped Hurricanes in the April – June 1940 period (see for example 1, 79, 151, 213 squadrons). Books from Richey, Gleed and Neil also mention that new Hurricanes came equipped with Rotol constant speed propellers prior to the Battle of Britain. Which propeller a Hurricane possessed in 1940 may be more a question of when it was built rather then where.

….Was it the case that Gloster-built Hurricanes received the Rotol whereas Hawker ones had the DH?….

No. The first Gloster batch had a mix of DH and Rotol.
Geographic link most unlikely.
I might be wrong but I think you will find that when Hurricanes were first despatch to N Africa there was a preference for DH in that theatre.

Initially there was a considerable advantage to be gained using the Rotol propeller: it was a constant-speed unit rather than the DH variable pitch propeller, which could only be used in the two extreme positions (fine and coarse pitch). The Rotol propeller was initially allocated to the Hurricane because it was thought to be more in need of improvement. At the same time a programme was set in motion to redesign the DH propeller from vp to constant speed: this resulted in a kit being produced which was fitted to Fighter Command’s aircraft (those still with vp props) in July 1940. After this time the performance difference between the two was small.

I agree that it would have been geographically convenient to fit Rotol props to Gloster-built aircraft in preference to Brooklands ones – but did this actually happen? When were enough Rotols available to replace the DH on the Hurricane Mk.1 line – if this did ever happen?

The prime reason for more than one supplier was in case, for whatever reason (enemy action being predominant), a source of supply was cut off of one particular design.

The fact that Gloster-built Hurricanes received Dowty-Rotol (Cheltenham) props may have just been a fortunate geographical co-incidence.

There wasn’t any major performance advantage for any particular type though servicing and repairs differed between different designs and constructional materials.

Anon.