I have had a long and troubled relationship with solid rubber tyres on Garrett undertype wagons. This started in 1991 when I was firing for Richard Sadler on his four wheel undertype no 35465 built in 1931. We had set off to London to join the H.C.V.S. London to Brighton Run at about 04:00 from Thaxted in Essex. We were making good time, which was unusual because my skill at firing a Garrett wagon, having had more experience on Foden 6 ton overtype wagons, left something to be desired. I tended to keep a thin, level fire; this does not work with a Garrett undertype, which soon pulls holes through a thin fire, allowing cold air into the firebox and cooling the superheater. On this occasion I had followed Richard's instructions more closely and had a thicker fire. At about 30 miles, I had my head down firing and there was a loud crack, followed by a smell of hot rubber. Richard pulled up and we got down to investigate. Initially all looked well but a more detailed inspection revealed tell-tale splashes of molten rubber on the chassis and a split in the inside wall of the near side tyre. Hysteresis of the rubber causes the tyre core to increase in temperature and the low conductivity of the rubber allows the temperature to build up and melt the core. The wall of the tyre then bursts and hot liquid rubber is ejected from the tyre. After this event it was not possible to continue travelling at the rate we had progressed so far. Reluctantly, we turned around and limped back to Richard's yard on the A10. Richard had experienced this problem once before with new tyres and decided that the best option would be to put back the tyres that were on the wagon when he obtained it. These were older Dunlop tyres but had some flats worn on them. The tyres were trued up using a tread cutter and it was found that the older tyres performed reliably on many subsequent occasions.

120x741 1200

The front axle with the replacement tyres made from two narrower section tyres. 

When I obtained the chassis of my wagon (Garrett 34841) it had been stood for at least 30 years in the nursery where it was found. The front tyres appeared to be unusual because there was a line along the centre of the tyre face and there were two steel bands on the wheel. The rubber was completely debonded in several places around the wheel and so it was decided that the tyres would have to be replaced before it could be used on the road. The tyres were marked 120 x 741 and were "Spencer Moulton" brand. Solid tyre sizes on British vehicles were usually metric, in this case 120mm was the width of the tyre and 741mm was the diameter of the rim it was made to fit. The original tyres would have been 180 x 720 and we realised that the rubber had been removed from the original steel bands, which were left on the wheel. The 120mm wide tyres had been cut down to 90mm width and pressed onto the front in pairs over the original tyre bands. I understand that the larger wheel diameter coincided with that of some London General Omnibus Company front wheels; there would have been a large surplus of these tyres when buses were converted from solid to pneumatic tyres. I cut the tyres off using an angle grinder, which was a very messy procedure. This revealed that the old tyres were produced on steel bands with multiple grooves cut into the surface. A hard rubber compound, referred to as "ebonite" or "vulcanite", was used to bond the softer elastic to the steel band. on their later tyres Dunlop used plain steel bands and bonded the rubber direct to the steel

tyre d

A rear wheel with the rubber removed to enable the band to be cut. On these old tyres, the rubber has parted to allow the tyre to become loose. The centre strip of rubber that remains had firmly bonded to the steel band as a reult of the serrated grooves turned into the band.

A pair of 180 x 720 tyres was obtained from John Lea in exchange for some Foden parts that I had acquired, when searching for Garrett bits. These were pressed on at Watts Tyres in Sheffield using their fairly modern hydraulic press which they used for pressing tyres onto the manipulators used in the local steel forges.

The original rear tyres were in poor hard and cracked but looked as though they might have a few miles left in them; so they were kept for the first few years; which included a visit to the Long Shop Museum at Leiston where 34841 was originally built. After this trip the tyres had done about 800 miles and were starting to deteriorate rapidly; the rubber was coming away from the steel band and emitted a creaking sound whilst moving. The tyres are 160 x 850 and the search for replacements was long and difficult with several disappointments along the way with offers of tyres that did not materialise. Eventually I obtained a pair of the correct size Dunlop tyres and a pair of 180 x 850 Henley tyres, which had to be reduced in width before they could be fitted. These tyres were pressed on at Watts Tyres in Sheffield in July 2002, as with the front tyres. Watts did not have the required tooling to press the large rear tyres and so I borrowed a 900mm square, 25mm plate from a steel fabricator who was local to me. The tyres were pressed on successfully but the plate ended up slightly dished. Unfortunately Watts no longer operate from that site. and I have had to find other tyre presses.

 Dcp 10301200

Watts tyre press in Sheffield pressing on the rear tyres. The third tyre is being used as a spacer to allow the tyres to be pressed past the chain sprocket.

DCP 10421200

 The rear wheels back at home with the new tyres fitted. 

The set of new tyres on the rear are still performing well, having been fitted in 2002. The front tyres, which are subject to higher loadings than the rears, were worn out by 2014 and were replaced with a pair of new, old stock, 8" x 720mm Dunlop tyres that had been cut down to 180mm wide to fit the wheels. These were pressed on at Yorkshire Industrial Tyres in Barnsley. This firm had a proper solid tyre press. The main features which made it differ from Watts' press are that the ram pushes upwards from below rather than down from the top of the press. There is also a table that swings out to facilitate loading of the wheel and tyres onto the press.

tyre a

The front wheel on the press, an old tyre band had been cut to provide a spacer to support the dished wheel and to allow the old tyre to be pressed off. The tear drop shaped table swings out from above the ram.

tyre b

The front wheels with new tyres fitted.. 

tyre c

The old tyres, appear to have a lot of wear left on them but are debonding from the band, cracking and with flat spots forming. (28th April 2014)

The wheels were duly refitted to the wagon and in May 2014 Andrew Hawkswell accompanied me as we ventured through Brighouse and Elland onto the A640 to cross the Pennines to attend a show at Ellenroad Mill Engine and steam Museum. The run across was pleasant with a few challenging hills. On the return journey we had successfully climbed out of Greater Manchester (what we commonly refer to as Lancashire) and were on the long descent towards Huddersfield. Just as we were approaching Nont Sarah's, a public house just above Scammonden Reservoir, we heard an unusual crunching noise, following which what looked like a large rubber 'O' ring was seen bounding down the road ahead of us. Fortunately, at that time there was no traffic and the rubber from the tyre came to rest about 100 yards away in the opposite verge.

The wagon at the side of the road with missing rubber from the near side tyre. (5th May 2014)

A closer view of the wheel without rubber. Some slivers of rubber can still be seen attached to the steel band.

The rubber unceremoniously dumped on the back of the wagon.

Thirteen miles from home on a Sunday evening was a depressing prospect since at the time Nont Sarah's was not trading and it does get rather bleak up there. Mobile phones came to the rescue (did they have them in the 1920s?) and with the help of a few friends we were able to arrange for a low-loader to come and pick us up and take us home. The tyre had only been on the wheel for just under 8 days, had run 47 miles and was now scrap. The other front tyre looked as though it was in the process of debonding from the steel band and it was considered that it would be prudent to replace it as well.

This was not a time to despair. Having supplied a pair of new old stock 8" x 720mm tyres to Derek Gransden when he had one of his Sentinel DG6 front tyres fail on the Sentinel Drivers Club run from Glasgow to Shrewsbury, the old tyres came to me. The failed one looked good but had overheated and formed a gas pocket between the layers of rubber. This could be detected by the tyre having swollen at that point and when tapped it sounded hollow. The other tyre was in good condition and so was selected to replace the near side front tyre. The front wheel was removed and another trip to Barnsley was made to fit the new tyre in time to attend an event at Upper Denby on 17/18th May, about 16 miles away. The journey there and back went well and both tyres were intact on our return. However, when I looked at the wheels a couple of days later the other tyre on the off side was starting to extrude past the rim where the weight was applied. I jacked up the wagon to turn the wheel and saw that there was now a large flat where the tyre had been resting on the floor. This had not recovered after a few days and so I concluded that the second tyre was also scrap

So, another trip to Barnsley was arranged. The only other tyre that I had of the correct diameter was a 160mm x 720mm tyre that I had acquired a long time previously. This had been made by the long defunct St Helens Rubber Co. and, although it was unused, appeared to be perished and cracked. However, from my earlier experinces with the tyres that were on the rear of the wagon, older tyres seem to be harder wearing than the newer Dunlop tyres. The front wheel was removed from the wagon again and taken down to Barnsley on 24th June 2014 for the replacement tyre to be pressed on.

The 160mm x 720mm tyre was pressed on to the centreline of the wheel and so there was 10mm of
steel wheel perimeter visible on the inside and outside faces. (28th June 2014)

The St Helens tyre didn't look pretty and was undersized (the same size as fitted to four ton Garrett wagons) but it performed well until it was replaced in March 2015 after having run about 300 miles..

A search for replacement tyres was not proving to be successful and so the manufacture of some new tyres was investigated. Tyres for traction engines had been made by vulcanising rubber onto the wheels but I was not aware of new solid rubber tyres being made in the UK that had been used on the front axle of an undertype steam wagon. In my opinion, these are probably the most highly stressed tyres to be used on preserved vehicles. Not only are they heavily loaded with the boiler being forward of the front axle,they are narrow, subjected to high road speeds and with the diameter of the wheel being small relative to traction engines are subject to compression and relaxation at a much faster rate. Enquiries were made to several firms and it was concluded that polurethane might be the best material to use. One of the old Dunlop tyres was sent to Jobel Engineering in Cornwall and they removed the old rubber and made a new tyre. The steel bands for the older Dunlop tyres are much thicker than the later ones and have a series of grooves in the perimeter to improve the bond of the rubber.

The new 180mm x 720mm polyurethane tyre manufactured by Jobel Engineering.

The new tyre was delivered in early March 2015 and was taken with the wheel to Barnsley at the end of March to be pressed on. It pressed on very easily without much force; the tyre manufacturer had cleaned up the inside of the steel band, removing all the loose rust and scale. I refitted the wheel and went for a trial run on 6th April 2015 (Easter Monday) and within 1/4 mile the tyre and steel band were half way off the wheel. I limped home, knocked the tyre back onto the wheel and then retired to consider my next course of action.

The new tyre working its way off the wheel after only 1/4 mile run.

The options that I could think of were: 1. Weld the tyre to the wheel or 2. Press the tyre off and then press it back on over a piece of wet canvas. I did not want to risk melting the polyurethane and so opted for option 2. The wheel and tyre were taken to the newly opened Yorkshire Industrial Tyres depot in Wakefield on 18th April,where the tyre was pressed off and then refitted over a heavy linen table cloth. This required a substantial amount of force, which was quite reassuring. The following day the wheel was refitted to the wagon and taken out for a trial run, which was successful.

The new tyre being pressed on over a heavy linen table cloth

The polyurethane tyre is harder than the "new" Dunlop on the near side and seems to give a slightly rougher ride. However, the new tyre stays a lot cooler than the Dunlop. Since then up to 2022 we have done about 1000 miles on the new tyre, which includes a trip to Ipswich in September 2015. So far the tyre has been trouble free and I have since had another tyre manufactured, ready for fitting when necessary.

If you have any further questions or information on this subject, please feel free to contact Michael Walters