A rare Priestman

[FOWLER MAN]

Hi,
I was looking through some old pics. when i noticed this Priestman in the corner. I thought it was a 108 till I noticed the twin boom rams, it was "The rare 168"
I ran one of them in the 1980s, it came to me Ex. Marples Ridgeway & Kier. She was painted grey and blue, but sadly i have no pics. of it.

Priestman 168.jpg

It was a powerfull 17 ton machine with some good features, It was powered by a Ford 380 turbo engine and used Priestmans three pump hydraulic system.
This allowed the output from the third pump to be diverted on demand to any service opperating below 1900 pounds pressure. This doubled the flow to any service under light load,causing it to speed up and giving the same effect as variable displacement hydraulics. When traveling the third supply was devided equaly between both tracks. You also had full power to the front end whilst traveling, usefull for de-bogging.
One feature I have never seen on any other machine was the hydraulic track adjustment opperated through the rotary distributor from the hydraulic system.
The tracks which were slack whilst the machine was at rest would tension themselves immediately the engine was started.
Fred

[AJ.]

I'v been around a fair few machines in my near sixty years in the plant repair business and have never come across that type of track adjustment,I can't figure out why they would have gone to that trouble with a system that would be taking power from the engine all the time,how did they cope with the recoil,the grease adjuster came out round the mid fifties,I think it was on an AC 7G I came across it first,Terex had a system in the sixties that used nitrogen gas,many's the man got fooled by that,let the grease out to tighten the track and pump it in to loosen it,still anything was an improvement on the manual adjustment.I think there were less than a half dozen of the 168's made.
it's pity all those old British companies are gone.
AJ

[FOWLER MAN]

Hi A J,
Like you I can claim 55 years plus on the spanners too.
The first hydraulic grease gun adjusted track that I remember seeing was on the Fowler Challenger 4. They were introduced in 1953, they had planetary reduction final drives before their time too.

I well remember the Terrex nitrogen system, we had them on the 82-40s and I agree anyting was better than the big spanners and gas torch.
I remember wraping the screw adjusters in greased sacking to try to keep them free, we used to use the wrapping off the navy and scraper ropes.

As far as the 168 Priestman was concerned the advantage was that the tracks were always correctly tensioned, they even compensated for when the tracks filled with muck.
I never had trouble with the system so I don't know exactly how it worked, it certainly didn't take power from the engine to maitain the tension when at work. There was an isolator valve to allow you to turn off the system to work on the tracks, the hydraulic cylinder simply replaced the greasable one and the conventional recoil springs worked in the normal way.
Though I repaired machines in this area for Priestmans I don't know how many 168s were made but including my own I knew of four and there are two more pictured in this thread, thats six and I'm sure there were considerably more of them made, more than you think.
Fred

[FOWLER MAN]

Hi,
The rarest Priestman must be the 320.
I remember talking about them with Norman Taylor,Priestmans service manager when I was at The Works circa 1988.
Only three were built and the first one, (the prototype), was on navvy tracks.
The other two were sold into the Netherlans and the dealer out there had taken them back part Ex., they were offered to me.
I have only seen photos of 320 models, but i just found this Priestman sales promotion picture on the net. showing the real thing.
The 320 1s hiding behind a 220 in this pic.
Fred

Priestman 320 & 220.jpg

[Diggerpete1961]

I seem to remember the 168 was introduced by Priestman because the 160 was seen as over complex & over costly for the reduced circumstances of the late 70s / early 80s. The 160 was capturing less than 5% of the UK market in this size class by this time, it was years ahead of its competetors with servo controls & variable displacement pumps. The 168 was a 'big 108' with direct controls & triple gear pumps (a bit like the JCB 806 set up). I had no idea they were so rare. Locally to me Lineal Plant Hire of Newport Shrops had one in the late 80s (probably not from new). Also locally 160s were run by C.J. Pearce, Wrekin Construction, & one used by Hughes Plant of Ironbridge on a clay extraction site for a then local brickmaker - starting 1976, perhaps straws in the wind of how these 360 hoes were to be used as a mass excavation tool. A (fully hydraulic) 3RB was pensioned off to help buy the 160!. Rival local man Reg Anslow was still running a Hydrocub at this time. I actually drove it!. This would have dated from the same time as the 3RB, which an older relative had done time on. Strange that both these once groungbraking rival machines should be so local.

[the wizard]

Hello diggerpete yes you are right, I was buying a Priestman 120 direct from them in 1983 or 4 after Acrow went but before Sanderson took over under I cant remember quite which year (maybe Fowler man can confirm year they went under) when I was told then that the 160 cost to much to produce and when you see them you can believe it! The steel in the boom etc and travel /slew gearbox I was told more or less same as 220 .But one big regret was no servo on 168 but they wanted to keep cost down, but was a big 108. Was told once the 168 had problem with oil overheating , has anyone else heard the same? Bill

[bigkit]

Some of the newer Tacheuchi's have hydraulically tensioned tracks to