Which Hurricane Mk.Is had which props?

[Test Graham]

There's a nice picture showing on the SAAF Gladiator thread of K8040, Gloster's testbed Gladiator with variable pitch prop - probably the constant speed Rotol. The Rotol factory was in/near Gloucester, so that makes sense. This lead me to consider the problem of 1940 Hurricane Mk.Is, and which propellers they had. Production of the constant speed Rotol had begun in 1939, and Hurricanes had priority on fitting, but there was not enough to go round and Battle of Britain Hurricanes can be seen with DH props. I've never seen any comment as to which Hurricanes had which props. However, as the Gloster factory was making Hurricanes then it makes sense for Gloster-built Hurricanes to have the Rotols whereas Hawker-built Hurricanes would have the DH. Much as Spitfire Mk.Is from Supermarine had the DH prop whereas Mk.IIs from Castle Bromwich had the Rotol. Usually.

Has anyone come across any statement about arrangements made for the choice of propellers on Mk.I Hurricanes? How many, which ones?

I suspect I shall have to go trawling through photographs, but I'm not hopeful because for obvious reasons many/most showing the spinner/propeller don't show the serial.

I know that some very late Mk.Is had the bullet spinner of all later Hurricanes, but I'm thinking here of the earlier almost hemi-spherical one.

[gingerbob]

Perhaps it would help to focus initially on which Hurris had DH props. My impression is that the Hurri initially got the Rotol in favor of the Spit, which could better get by with the DH 2-position prop (as it was, until err, late June '40?) - both as replacement for 2-blade fixed-pitch prop, of course. So if DH becomes constant speed around late June, and Spit IIs begin rolling out with Rotol props about the same time, I wonder if Hurris were getting any DHs when they were still 2-position props?

bob

[Test Graham]

The Hurricane switched from the fixed pitch Watts to the variable pitch DH well before the war. Then the Rotol started to become available late 1939, I think December. Hurricanes got it rather than Spits, as you say, and the first ones are seen on Spitfires around the Dunkirk operations, but only one squadron to my knowledge. Between this time it will have been fed into the Hurricane production line as numbers built up

The assumption has to be that by this time (May) it was planned for enough Rotol were available to meet the demand for Hurricanes, so freeing ones for Spitfires. Whether this actually happened is another question. Alongside this is the expected (but delayed) appearance of the Spitfire Mk.II with the Rotol. Did Hurricane production switch over entirely, at one site or all sites, or did ones continue to be built with the DH?

Expressed in modelling terms, the problem is: given a known serial but no photograph for a Hurricane in this period, which prop should it have? Can we tell this from production records or do we have to work back from the evidence of similar-serialled aircraft in the same unit at the same time? Assuming we have even that, of course.

[gingerbob]

Looks like I'm going to have to delve into my records again!

The Spits (54 Sqn) were a trial, though I'm not certain whether a trial of Rotols (on fighters) in general, or Rotols on Spits specifically- I think (at least to a degree) the latter. If May is right for Hurris, then another element may be the fact that the Hurris were on the "front lines". I'll see what I can find.

bob

[Edgar]

[gingerbob]

Thanks Edgar, that's one thing I had, but more. To clarify a little, the 54 Sqn Spits were fitted several months before May (I think), and they were to evaluate the benefits of a constant-speed on fighters (or Spits).

bob

[Edgar]

One thing that might have shifted things along a bit quicker, of course, was that the Hurricane, with a wooden prop, couldn't have armour fitted behind the seat.

[Test Graham]

Getting rid of the Watts in favour of armour was clearly a Good Thing, but the heavier DH would have sufficed for that. Which is just as well if Rotols were not to be fitted retrospectively. One of the Belgian Hurricanes had a Rotol, but presumably this was an interned example.

Although I'm interested in this as a piece of history, I do have a specific query about building an aircraft of 607 Sq in France. These were from early in the Gloster line, which were delivered between 12/39 and 4/40 according to Mason. The P25xx and P26xx serials therefore are unlikely to have been built with the Rotol prop, if the introduction of these can be dated to late February. Mason doesn't have the second Gloster batch, which I am told was all Rotol (to be confirmed), starting until July, so I'm sure either this date or the end date of the first batch is wrong. He also has the third batch starting in July, so I suspect that it is the dates for the second batch that are wrong.

Mike Williams on the Key Publishers site Historical forum quotes an MAP memo of 29/6/40,"...the Hurricane I aircraft now being delivered from the manufacturers all have Rotol constant speed airscrews" so that at least gives us an end date for any "mix". How the production was split between end February to late June remains undefined.