ww11 aircraft tyres.

The reason tyres are filled with gas is that when load is applied (ie. landing) the gas will compress thus absorbing some of the shock. If the tyre was filled with water you would simply pressurise the liquid, making it act like hydraulic fluid and blow the tyre apart.

Although not if the A/C was flying at altitude, as the contents of the tyre would be,… ice!!

The reason tyres are filled with gas is that when load is applied (ie. landing) the gas will compress thus absorbing some of the shock. If the tyre was filled with water you would simply pressurise the liquid, making it act like hydraulic fluid and blow the tyre apart.

One thing that fuddles me about the idea of water ballast in tyres is that most (main) undercarraiges are fairly close to the c of g so what advantage would there be?

Roger Smith.

An odd thought crossed my mind. If the A/C is being used to tow target drogues, might this change the balance of the A/C and necessitate some ballasting somewhere? I’ve never heard of water ballasting tires, but have heard of weights being added to aircraft to balance out their flight dynamics. Anyone know how a towed drogue might affect flight characteristics? Depends on what aircraft and where tow cable is attached?

an interesting/plausable theory thankyou for that
regards vic:cool:

An odd thought crossed my mind. If the A/C is being used to tow target drogues, might this change the balance of the A/C and necessitate some ballasting somewhere? I’ve never heard of water ballasting tires, but have heard of weights being added to aircraft to balance out their flight dynamics. Anyone know how a towed drogue might affect flight characteristics? Depends on what aircraft and where tow cable is attached?

The red dot on the tyre is the light spot and is positioned next to the valve on the wheel, the tyre doesn’t have a heavy spot.

I was relaying what chap showing us around Fort Dunlop aircraft tyre manufacturing plant a couple of weeks ago. I’m sure he said that the heavy spot was marked by a red (or green?) spot and it was usually positioned diagonally opposite the valve.

Roger Smith

The red dot on the tyre is the light spot and is positioned next to the valve on the wheel, the tyre doesn’t have a heavy spot.

b*****. so close, but so wrong! (me, not you). Either way, NOT water…:D

I believe the heavy spot is usually positioned diagonally opposite to the valve which is a heavy spot on the wheel hub.

Roger Smith.

The red dot on the tyre is the light spot and is positioned next to the valve on the wheel, the tyre doesn’t have a heavy spot.

Water ballasting is common practice in increasing grip on agricultural vehicle tyres. They have special valves and normally antifreeze is added for obvious reasons.

Why you would want to add weight to an aircraft tyre may not be obvious but that doesn’t mean it is incorrect.

i agree ive just related the story as told to me i cant prove or disprove ,thats why i posted the thread ,thanks for the response
regards vic

Oh go on then, seeing as prolific posting and ‘cool’ symbols are all the rage…..
😎 😎 😎 😎 😎 :p

some watch others post,you dont find out unless you ask!:cool:

you need a few more smiley cools come on! project yourself push push!!!!!!!:)

Oh go on then, seeing as prolific posting and ‘cool’ symbols are all the rage…..
😎 😎 😎 😎 😎 :p

…. aircraft tyres are balanced at manufacture, and marked with a ‘heavy spot’ on the sidewall. On fitment to the wheel assy, the tyre heavy spot is lined up appropriate to the wheel’s balance…..

I believe the heavy spot is usually positioned diagonally opposite to the valve which is a heavy spot on the wheel hub.

Roger Smith.

With water???

I’d imagine the early tyres and spoked wheels were built in line with car tyres and wheels of the time, ie. lead weights attached to the rims, or some other similar weighting. By 1940, most wheels were constructed out of alloy as assemblies, and tyre weighting would have been done at construction by modifying the number or grade of plies or by adding internal weights between the plies. Lead weights would probably have been found to fall off due to the vibration and higher landing speeds.

This is all supposition by the way, since I am no expert on tyre development, only by comparison to modern kit…..

Any pre-war aircraft operators care to comment on how spoked wheel and cover assemblies are balanced?

I can’t see any reason why an aero spoked wheel would be in different from a car wheel of the period- tubular lead weights crimped to the spokes.

Water ballast inside a tyre. That does not sound right.

Mark

i collected some very large spoked aircraft wheels/tyres(6ft plus from up the dales (where i cant remember) however they were fully inflated when collected and the gentleman pointed out these had come from a large pre war biplane used as a target tug by the navy and the tyres had to be ballasted .:cool:

With water???

I’d imagine the early tyres and spoked wheels were built in line with car tyres and wheels of the time, ie. lead weights attached to the rims, or some other similar weighting. By 1940, most wheels were constructed out of alloy as assemblies, and tyre weighting would have been done at construction by modifying the number or grade of plies or by adding internal weights between the plies. Lead weights would probably have been found to fall off due to the vibration and higher landing speeds.

This is all supposition by the way, since I am no expert on tyre development, only by comparison to modern kit…..

Any pre-war aircraft operators care to comment on how spoked wheel and cover assemblies are balanced?

water ballasted tyres? Surely someone is pulling your leg… I can’t see any advantage to ballasting tyres in this way at all, unless someone want to shed some light on it. aircraft tyres are balanced at manufacture, and marked with a ‘heavy spot’ on the sidewall. On fitment to the wheel assy, the tyre heavy spot is lined up appropriate to the wheel’s balance. The tyre is then filled with Nitrogen. (Less expansion with altitude, but mainly used since it is an inert gas). Water does not feature in the process. I can only speak for modern (post war) tyres, but I can’t imagine the balancing process has changed much since before the war…

As said, Dunlop were (and are) a major supplier of aircraft tyres.

If I’m talking c**p, please tell me….:D

i collected some very large spoked aircraft wheels/tyres(6ft plus from up the dales (where i cant remember) however they were fully inflated when collected and the gentleman pointed out these had come from a large pre war biplane used as a target tug by the navy and the tyres had to be ballasted .:cool:

‘Palmer Aero’ was another.

Mark

Yes Dunlop. 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎

you need a few more smiley cools come on! project yourself push push!!!!!!!:)

who was the main supplier of rubberware for the RAf aircraft tyres either main undecarriage or tailplanes and were there many variants in size in respect of tailwheels plus were undercart tyres water ballasted?:cool:

Yes Dunlop. 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎 😎

water ballasted tyres? Surely someone is pulling your leg… I can’t see any advantage to ballasting tyres in this way at all, unless someone want to shed some light on it. aircraft tyres are balanced at manufacture, and marked with a ‘heavy spot’ on the sidewall. On fitment to the wheel assy, the tyre heavy spot is lined up appropriate to the wheel’s balance. The tyre is then filled with Nitrogen. (Less expansion with altitude, but mainly used since it is an inert gas). Water does not feature in the process. I can only speak for modern (post war) tyres, but I can’t imagine the balancing process has changed much since before the war…

As said, Dunlop were (and are) a major supplier of aircraft tyres.

If I’m talking c**p, please tell me….:D

Dunlop were the main supplier of tyres and tubes.

And not only for the RAF, A JU88 we recovered from Pitsea marshes, that was shot down in 1940, was fitted with Dunlops. The factory(s) in Germany still produced Dunlop branded tyres, albeit in control of the new masters;)