Spitfire main wheel tires - Smooth or with pattern

[FinnAndersen]

Any neat rule as to where and when Spitfires were fitted either with smooth tires or with patterned tires? 

 

I'm guessing that smooth tires were the norm with grass airfields, but is there more to it?

 

/Finn

[FinnAndersen]

Well, as all modellers know, when all options fail and nothing works, it's time to consult the instructions.

 

The reason for my question was that I had purchased a pair of threaded wheels. I had also purchased a pair of BaracudaCast smooth wheels and they provided the information needed: 

 

Quote " The block tread tyre did not enter service until after the war. It was fitted to postwar Spitfires that operated off concrete runways and carrier decks"

 

/Finn

[wmcgill]

Uncommon tyre with tread seen on Mk.Vb BM520 from June 1942 in this IWM photo. Follow the link and zoom in to the highest resolution version to see the tread detail

 

https://www.iwm.org.uk/collections/item/object/205210198

 

[Magpie22]

15 hours ago, FinnAndersen said:

Well, as all modellers know, when all options fail and nothing works, it's time to consult the instructions.

 

The reason for my question was that I had purchased a pair of threaded wheels. I had also purchased a pair of BaracudaCast smooth wheels and they provided the information needed: 

 

Quote " The block tread tyre did not enter service until after the war. It was fitted to postwar Spitfires that operated off concrete runways and carrier decks"

 

/Finn

 

Finn,

 

BarracudaCast is not strictly correct. RAAF Spitfires were using treaded tyres as early as 1943. 

As you suggest in your first post, smooth tyes were OK on large open fields, but treaded tryes gave the pilot better directional control on runways, particularly on the gravel or coral strips common in north Australia and the islands in the SWPA. They also wore longer.

 

I haven't studied the area closely but, I suspect, similar use of treaded tyres may apply to the desert and India/Burma thatres with the RAF.

 

Peter M

 

   

 

Left: A Mk.VC of No. 54 Sqn in January 1944.             Right: A Mk.VIII of No 549 Sqn mid 1944.

[FinnAndersen]

1 hour ago, Magpie22 said:

 

Finn,

 

BarracudaCast is not strictly correct. RAAF Spitfires were using treaded tyres as early as 1943. 

As you suggest in your first post, smooth tyes were OK on large open fields, but treaded tryes gave the pilot better directional control on runways, particularly on the gravel or coral strips common in north Australia and the islands in the SWPA. They also wore longer.

 

I haven't studied the area closely but, I suspect, similar use of treaded tyres may apply to the desert and India/Burma thatres with the RAF.

 

Peter M

 

   

 

Left: A Mk.VC of No. 54 Sqn in January 1944.             Right: A Mk.VIII of No 549 Sqn mid 1944.

Aha, this was what I was suspecting. Unfortunately the pictures do not show, but I trust you and, as always, I would ideally need photographic evidence of a particular plane.

 

Thanks

 

/Finn

 

[Magpie22]

Finn,

Do you have a particular A/C in mind? If it's RAAF I can check my records to see if I can be more definitive.

Peter

 

[FinnAndersen]

2 hours ago, Magpie22 said:

Finn,

Do you have a particular A/C in mind? If it's RAAF I can check my records to see if I can be more definitive.

Peter

 

I'm doing these two from Eduard Aussie Eights Spit VIII UP-F A58-517 and Spit VIII ZP-V A58-631  Grey nurse.

 

Possibly also Spit VIII QY-V A58-429 "Rima III" as I have done "Rima II". Was there ever a "Rima I" ?

 

/Finn

[Phoenix44]

10 hours ago, Magpie22 said:

 

Finn,

 

BarracudaCast is not strictly correct. RAAF Spitfires were using treaded tyres as early as 1943. 

As you suggest in your first post, smooth tyes were OK on large open fields, but treaded tryes gave the pilot better directional control on runways, particularly on the gravel or coral strips common in north Australia and the islands in the SWPA. They also wore longer.

 

I haven't studied the area closely but, I suspect, similar use of treaded tyres may apply to the desert and India/Burma thatres with the RAF.

 

Peter M

 

   

 

Left: A Mk.VC of No. 54 Sqn in January 1944.             Right: A Mk.VIII of No 549 Sqn mid 1944.

I'm curious why that should be so? The highest grip is provided by a tyre with no tread patterns, as we see with slicks in racing. Tread patterns are used to avoid aquaplaning as the pattern removrs water from the surface of the tyre.  A crosstread pattern may be used for greater grip on soft ground but it needs to be pretty soft to work. I'm not sure how a tread pattern would give greater directional control when it has less grip nor how it would wear less quickly as a tread pattern means less rubber doing the same amount of work? A tyre with no tread pattern also offers the greatest braking ability, a pretty key factor. And as we see with modern airline tyres, as aircraft rarely need much grip turning on the ground (taxi speed only) simple circumferential grooves are the best for water removal. Where there's little rain - the desert say - there  should be no need for a tread pattern. Conversely where there's a high risk of standing water on a runway you would want a tread pattern, which is perhaps why the RAAF were early users?

[Michael louey]

13 hours ago, FinnAndersen said:

I'm doing these two from Eduard Aussie Eights Spit VIII UP-F A58-517 and Spit VIII ZP-V A58-631  Grey nurse.

 

Possibly also Spit VIII QY-V A58-429 "Rima III" as I have done "Rima II". Was there ever a "Rima I" ?

 

/Finn

HI Finn,

 

Peter will probably have more definitive information however to answer some of your questions -

 

The Aussie Eight book has a picture of A58-517 with block tyres. I would have expected most operational RAAF Mk VIII's (and probably Mk Vc's) to have block tyres due to the rough fields in Northern Australia and the islands up north.

 

Regarding Lou Spence's various Rima's. I have a book written by his son. He says Rima 1 was Lou's P40 which he flew in 3 Squadron in the Middle East. I don't see any photos showing Rima III's tyres and the picture of Rima II showing the tyres - the tyres are pretty dark though I think they look treaded.

 

If you're modelling "Rima III", check my build as you'll need to change the order of the code letters on the starboard fuselage regardless of whether you build it with clipped wings or not.

 

Cheers

 

Michael

[Magpie22]

9 hours ago, Phoenix44 said:

I'm curious why that should be so? The highest grip is provided by a tyre with no tread patterns, as we see with slicks in racing. Tread patterns are used to avoid aquaplaning as the pattern removrs water from the surface of the tyre.  A crosstread pattern may be used for greater grip on soft ground but it needs to be pretty soft to work. I'm not sure how a tread pattern would give greater directional control when it has less grip nor how it would wear less quickly as a tread pattern means less rubber doing the same amount of work? A tyre with no tread pattern also offers the greatest braking ability, a pretty key factor. And as we see with modern airline tyres, as aircraft rarely need much grip turning on the ground (taxi speed only) simple circumferential grooves are the best for water removal. Where there's little rain - the desert say - there  should be no need for a tread pattern. Conversely where there's a high risk of standing water on a runway you would want a tread pattern, which is perhaps why the RAAF were early users?

 

Slicks work very well on racing cars and dragsters running on a good smooth, sealed, surface that is dry and dust and pebble free. Their main requirement is to get maximum power down to the ground as well as maximum braking.  Your F1 car does not handle very well when sand blows on to the track  or they hit the "marbles". How many rally cars have you noticed running slicks?

 

With tail-wheel A/C, maintaining directional control during take off and landing depends very much on the effectiveness of the rudder. Using differential pneumatic braking, while effective at taxiing speeds, is rather crude when you are hurtling down the runway at high speed.

 

As well as a corrective moment to straighten the aircraft, the rudder also applies a lateral force . While the moment will tend to 'point the nose' and correct the aircraft's path, the lateral force tends to cause the mainwheels to slide sideways. This is resisted on a hard sealed runway but, on a loose surface, (e.g. gravel, coral, sand), the tyre will slide and the aircraft will track sideways across the runway, not very desirable. Circumferential grooves in the tyre reduce this effect. Cross tyre grooves allow the tyre to flex and the blocks to flatten, keeping more rubber in contact with the runway. Braking effectiveness was less important than directional control as fighter A/C normally operated from runways with adequate length, although some of the advanced strips were very marginal.

 

The cross-section of the treaded tyre also seem to be less 'pointy' than that of the smooth tyre, which would bring more surface are into contact with the runway to compensate for the reduced rubber area. All photos are of Mk.VC A/C

 

        

 

Accidents still happened!! Skidded off wet runway in downwind landing. Pilot nearly drowned as his head was underwater in a ditch.

 

 

I do recall that we had circumferential grooved tyres on our Sabres and Mirages. Helped in tracking straight before you dropped the nose wheel.

Airliners with multi wheel bogies are a whole new ball game.

[cactuswest]

Hello @magpie,

Your description of how the rudder works is not entirely accurate. I am not sure what you mean with the rudder lateral force will somehow force the airplanes sideways. Only a crosswind while landing can do that in extreme condition. In no wind condition or if the wind is straight down the runway you can land on a very slippery runway if you have enough distance to stop.

On many airfields circa 1940 the "runway" was so wide that you always could takeoff and land into the wind.

On tailwheel airplanes the danger zone on landing comes when the rudder is becoming ineffective as the airplane slows down, this is because you are losing your only aerodynamic directional control mean. You are two slow for the rudder and potentially too fast to use the brakes. Furthermore as the tail of the aircraft comes down the propeller, which is a gyroscope, pulls the aircraft to the right (to the left when raising the tail). Conventional landing gear configuration types are a piece of cake to land in comparaison.

As far as airliners there are no differences in terms of airplane handling single, double or triple boogies.

Maybe I did not understand your post. 😀 

[Magpie22]

18 hours ago, FinnAndersen said:

I'm doing these two from Eduard Aussie Eights Spit VIII UP-F A58-517 and Spit VIII ZP-V A58-631  Grey nurse.

 

Possibly also Spit VIII QY-V A58-429 "Rima III" as I have done "Rima II". Was there ever a "Rima I" ?

 

/Finn

Finn,

 

As Michael points out, photos of A58-517 clearly show treaded tyres.

 

As regards A58-631, I do not have a photo that positively confirms that it had treaded tyres, but every shot I have of No. 457 Sqn HF.VIII A/C, where I can see the tyres, shows them with treaded tyres.

 

"Rima III" may have had smooth tyres. As Michael says none of the photos of that A/C show which tread. A very few photos do show some of the early LF.Mk.VIII still wearing the smooth tyres they had when delivered. The strips at Livingston and Strauss were both good sealed surfaces and the smooth tyres would have been adequate. However, I would go for treaded.

 

"Rima II". A58-254 was initially QY-F. When she was pranged in Feb 1944 she was fitted with treaded tyres. After she was repaired and became Spence's QY-V, I think it would be reasonable to assume she would still have had treaded tyres. She certainy had them much later when with CGS.

 

The Rimas. As Michael stated, the first Rima, (not Rima I), was a No. 3 Sqn Kittyhawk CV-O, possibly AK698 or AK612.

Spence's fist Spitfire VC with No. 452 Sqn was A58-240, QY-D, which he inherited from the previous CO, S/L MacDonald. She carried Spence's rank pennant and was named "Rima" . She was pranged by another pilot in April 1944, shortly after Spence had led the squadron in the epic flight to Perth and back. A58-254, previously QY-F, was repaired following an accident and became Spence's QY-V, "Rima II", in April 1944. 

 

Cheers,

Peter

[FinnAndersen]

2 minutes ago, Magpie22 said:

...

Spence's fist Spitfire VC with No. 452 Sqn was A58-240, QY-D, which he inherited from the previous CO, S/L MacDonald. She carried Spence's rank pennant and was named "Rima" . She was pranged by another pilot in April 1944, shortly after Spence had led the squadron in the epic flight to Perth and back...

Ah, so there was a Spitfire "Rima" before "Rima II". 

 

I think I'll pass that one, as I already have a Spitfire Vc associated with Lou Spence.

 

The P-40 sounds interesting and combined with the final Mustang, I'd have a fair selection of his mounts.

 

It is a very interesting and in some ways challenging way of building a collection of models, having the personal story behind the little toys I make 😜

 

Thanks again, you never disappoint me.

 

/Finn

[Magpie22]

Finn, I tried to send you a message, but got the diagnostic that you "cannot receive messages". Is your box full?

Peter

[Tail-Dragon]

2 hours ago, cactuswest said:

Hello @magpie,

Your description of how the rudder works is not entirely accurate. I am not sure what you mean with the rudder lateral force will somehow force the airplanes sideways. Only a crosswind while landing can do that in extreme condition. In no wind condition or if the wind is straight down the runway you can land on a very slippery runway if you have enough distance to stop.

On many airfields circa 1940 the "runway" was so wide that you always could takeoff and land into the wind.

On tailwheel airplanes the danger zone on landing comes when the rudder is becoming ineffective as the airplane slows down, this is because you are losing your only aerodynamic directional control mean. You are two slow for the rudder and potentially too fast to use the brakes. Furthermore as the tail of the aircraft comes down the propeller, which is a gyroscope, pulls the aircraft to the right (to the left when raising the tail). Conventional landing gear configuration types are a piece of cake to land in comparaison.

As far as airliners there are no differences in terms of airplane handling single, double or triple boogies.

Maybe I did not understand your post. 😀 

I have been flying tail dragger aircraft for 42 years, and agree almost completely with your comments with one exception. The word "conventional" usually  refers to tail draggers, not nose wheel airplanes (tricycle gear). Landing tail draggers has been described many ways, but never "a piece of cake"!

[FinnAndersen]

1 hour ago, Magpie22 said:

Finn, I tried to send you a message, but got the diagnostic that you "cannot receive messages". Is your box full?

Peter

No. As far as I can determine, I've used 1% of available message space. I'll try to send you a messge with my email.

 

/Finn

 

[FinnAndersen]

1 hour ago, Tail-Dragon said:

I have been flying tail dragger aircraft for 42 years, and agree almost completely with your comments with one exception. The word "conventional" usually  refers to tail draggers, not nose wheel airplanes (tricycle gear). Landing tail draggers has been described many ways, but never "a piece of cake"!

Seems that we have some thread drifting going on?

 

/Finn

[Tbolt]

On 2/19/2022 at 6:39 PM, wmcgill said:

Uncommon tyre with tread seen on Mk.Vb BM520 from June 1942 in this IWM photo. Follow the link and zoom in to the highest resolution version to see the tread detail

 

https://www.iwm.org.uk/collections/item/object/205210198

 

 

Do you know what the deal is with the five colour roundel on that aircraft?

 

[Graham Boak]

I suspect a local repaint from an A roundel with the smaller central red to an attempt at a C roundel with a narrow white ring.

[Tbolt]

3 minutes ago, Graham Boak said:

I suspect a local repaint from an A roundel with the smaller central red to an attempt at a C roundel with a narrow white ring.

 

Yes maybe they just used a brighter red. Thanks Graham.

[iainpeden]

Off at a tangent. A couple of weeks ago I was talking to a visitor to the Spitfire exhibition at Duxford; he had been involved in the restoration of one of them so knew what he was talking about.

We got chatting about wheels and he mentioned that some Spits used hub caps on the main wheels - nothing I had heard before so can any one elaborate?

[Tbolt]

57 minutes ago, iainpeden said:

Off at a tangent. A couple of weeks ago I was talking to a visitor to the Spitfire exhibition at Duxford; he had been involved in the restoration of one of them so knew what he was talking about.

We got chatting about wheels and he mentioned that some Spits used hub caps on the main wheels - nothing I had heard before so can any one elaborate?

 

Not a Spit expert but the first production Mk.I seemed to have used a dome type.

 

 

 

This seems to be the standard later, flat type (though this first picture is from the 1970's)

 

 

Here's the Mk.IX, MH434 with wheel covers.

 

 

Here's a Mk.V with them on.

 

 

As does the Mk.V from the discussion above.

 

 

A few more.

 

 

 

 

 

A Mk.XII with covers.

 

 

Aires do a set as do Ultracast.

 

 

 

[iainpeden]

Thanks @Tbolt, you learn something everyday.

[Geoffrey Sinclair]

Back to RAAF Spitfire tyres.  In December 1943 the RAAF began durability tests for locally made tyres on Spitfire A58-315 and found they were worn through to the canvas in 10 flights using concrete taxiways and runways but did better on non concrete runways.

 

Any further details?

[cactuswest]

16 hours ago, Tail-Dragon said:

I have been flying tail dragger aircraft for 42 years, and agree almost completely with your comments with one exception. The word "conventional" usually  refers to tail draggers, not nose wheel airplanes (tricycle gear). Landing tail draggers has been described many ways, but never "a piece of cake"!

Hello @Tail-Dragon,

I did not mean taildraggers are a piece of cake to land. Au contraire.  I misspoke. I meant tricycle gear.