WW1 Dennis truck find

[Old Bill]

Are those two speed plus reverse gear boxes or ? What was the max speed of those trucks on good smooth roads?

 

 

These lorries have four speed and reverse boxes, all of the crash variety. Changing speeds takes practice but there is great joy to be had in a quiet change! The straight-cut gears have a very distinctive sound to them so one can instantly recognise a genuine veteran lorry on the road.

 

I expect the Dennis will be flat out at 20mph but it has a governor which should be set to 14. Whilst we will replace the linkage, I think I will leave the butterfly out of the inlet manifold as having a governor is just one more thing to catch you out, driving in modern traffic. 12mph, the legal top speed for a solid-tyred commercial vehicle, sounds slow but doesn't feel it as the lorry is quite happy. The great advantage is that one is never stuck in the middle of a queue of traffic, being generally at the front!

 

Steve

[Rick W]

Where do you get the tech info for tolerances etc?

[Old Bill]

Just make it up as we go along!

 

Seriously though, we just follow good engineering practice. We were very fortunate with the FWD that the manual was so comprehensive that it gave dimensions for such things as the carburettor jets so we had something to go on. The British lorries are much less well documented and occasionally we get it wrong. At least we can learn and have another go.

 

Steve

[abn deuce]

No need to explain about the low speed as I m sure with the solid tires and very stiff suspention along with less than tight steering that those speeds are quite a handful on good roads and if the surface was loose gravel or had a few good pot holes than you would feel more inclinded to travel at a far slower speed .

[Sisu]

Tim,

thanks for showing us these very interesting photos!

 

To reply your earlier question, I try to translate the Finnish text as well as I can (the limitation is my English ).

 

1st picture:

The time of wood gas

On the truck reads: "Water pipe shop - Huber" (ie. plumber shop in todays language)

(My comment: As can be seen this truck is running by burning wood on the round "oven" behind the cab)

 

Text below the picture says: "Packard from 1920 using wood gas. The register plate tells this truck has been in use on 1940, and likely during the whole war. Like the old men, some old trucks could do their service at the home line, when the young ones were "somewhere far". This truck was also playing its part for the water services of Helsinki, where the bombings had caused damage.

(My comment: Not only does the register plate tell this was taken around 1940, it also has the wood gas equipment which were installed on the vehicles during 1939-40).

 

2nd picture:

The picture is taken from Helsinki, close to the city center, name of the building is Government Palace by Senate Square. Government Palace houses the Prime Minister's Office, the Office of the Chancellor of Justice and most of the Ministry of Finance. Its been usual having great parades on the Senates Square. On the left side of the picture is the commander of Finnish troops and later the President of Finland, Carl Gustaf Mannerheim ("Marski"). He's standing at the first steps of Helsinki Cathedral. I can't quite date the photo, I tried to look for similar photos from the time but didn't find anything that could match it.

 

Another old parade picture from the same place:

 

Here's the Goverment Palace today:

 

And here's the church and the steps where Mannerheim was standing (Senates Square seen in front of the picture, the Government Palace is unseen on the right):

 

3rd picture:

Unfortunately I can't recognize the building, so it could be from elsewhere than Helsinki. All are Finnish soldiers, but I guess from their uniforms that their are from a vehicle service unit. Its hard to give exact answers when all my reference books are stored in England and I'm here in Germany

 

...and another interesting picture, I'm sure you know immediately what this is - especially after you look at the two-function wheels :cool2: Army had several of them, note the register plate "SA 295", SA = Suomen Armeija (Finnish Army) and the number is kind of a serial number which was given to new vehicles in the order they were put to service. Exceptions were the first numbers which were given in the order of importance, for example Mannerheim had SA 1 on his four (!) cars (I bet he was the only person in the Finnish history to have the same number on more than one car), after he died they never gave the number to anyone else.

 

As soon as I get a hold of my reference books, I can list all the early Finnish pre-war military vehicles and their numbers.

 

Cedric

Edited May 18, 2008 by Sisu

[Old Bill]

Wow, Cedric! What fantastic information! It just shows how much knowledge and information can be brought together by this forum!

 

Thank you for sharing that with us. It is another corner of military history about which I knew nothing but am very pleased to hear.

 

Steve

[Great War truck]

Tim,

 

 

...and another interesting picture, I'm sure you know immediately what this is - especially after you look at the two-function wheels :cool2: Army had several of them, note the register plate "SA 295", SA = Suomen Armeija (Finnish Army) and the number is kind of a serial number which was given to new vehicles in the order they were put to service. Exceptions were the first numbers which were given in the order of importance, for example Mannerheim had SA 1 on his four (!) cars (I bet he was the only person in the Finnish history to have the same number on more than one car), after he died they never gave the number to anyone else.

 

As soon as I get a hold of my reference books, I can list all the early Finnish pre-war military vehicles and their numbers.

 

Cedric

 

Cedric

 

Brilliant! I didnt think that you would be able to find such interesting information. Marvellous how all this comes together. The photo is a Pavesi. I did not know that they went that far. Very interesting.

 

Tim (too)

[Sisu]

No problem!

 

Tim is right about the Pavesi, I can't quite remember but I think there were four Pavesis in the Finnish Army and the trucks had seriously low power.

 

Looking at your gearbox rebuild photos, I noticed you have at least 4-5 crow bars on the floor - tells something about the nature of your project

 

What sort of seals on axles or safts are used in the gearbox? I guess Stefa's were not invented yet? How were the rubber parts like, could you actually trust rubber as a sealing material on those years? Stupid questions, but your trucks are so old I have no clue! I did some research on this subject and realized O-rings were invented on 1896. I guess Stefa-patent came after 30-40's?

 

Its interesting to learn if you can use current standard seals or do you make them yourself? I noticed Trelleborg, as the maker of Stefa's, O-rings and other seals, is also offering O-ring Calculation Program for free to easily specify the seal dimensions (this might be help for us with lesser knowledge): http://www.tss.trelleborg.com/us//www/en/service/Member-Registration-Benefits.jsp?josso_back_to=http://www.tss.trelleborg.com/us//www/en/service/o_ring_calculator/o_ring_calculator_1/O_Ring_Calculator.jsp

 

And how about the bolts, Whitworth, inch or another system? You must have some difficulties acquiring correct bolts for your project!

 

Cedric

Edited May 19, 2008 by Sisu

[Old Bill]

Yes, crow bars, big hammers, cold chisels, propane torch and hack-saw. Getting it all to bits without doing any more damage is the hardest part!

 

Oil seals are not really an issue because there aren't any! Well, not many anyway. At the half-shaft inner ends there is a leather washer and the gear change shafts are sealed with a gland which traps a coil of graphited yarn. Those are about it though. It is not called a 'total loss' system for nothing!

 

Bolts are an issue as it is very important to us to use the right thread type. The Dennis uses BSF threaded bolts which we can get. Whitworth are more difficult but we have a friendly specialist bolt supplier who contacts his friends to see what he can find for us. Also, our friends keep rummaging in their garages for tins of mixed bolts which all come in very useful although they are invariably rusty and need a good clean. One point is that the more modern bolts from after about 1930, have writing on the heads which makes them look wrong. We always put them in the lathe and machine them off before using them.

 

We are not so picky about the thread type in the coach bolts used in the body. However, they must have square nuts to look right. Square nuts really are a problem so we have been importing them from the US as hand luggage every time one of us goes over to see the relatives. Airport security men often look surprised when we pass through!

 

The silly things we do for fun......

 

Steve

[Sisu]

Many thanks, Steve - this is all very interesting and great information. Sounds like this is one of the things that separates the early vehicles from later ones - I'm not sure everyone would see so much effort for the bolts only. Everytime I touch a crow bar or a big hammer, something will break up - so I guess you have mastered the technique!

 

Its not often you see early vehicles listed with full engine output numbers. I'm especially interested what is the horsepower and torque rating in such machine? As they didn't put out too much horsepower, I guess they had to make more torque to be able to move the loads at all, or was the gearing different? What is the usefull revolution range for the engine? Its for sure that you have to match revs and gears before you make a gear change, but how easy its to stall the engine when you start moving? Like I said, I have only stupid questions - but I'm interested of the drivers point of view, what it was like in the old days. They had to drive on much worse roads, full rubber tires and there wasn't much protection against the elements. On top of everything, I guess they experienced some reliability problems with their trucks, so being a truck driver must have been a hard job (but I guess they were proud of their jobs)! Sure, they didn't drive such long distances as today - I suppose the long distances were done with trains in England? Do you have any idea how many miles per year they were driven in the old days?

 

Cedric

[Old Bill]

Yes, we break things too often as well. The hardest judgement is when one decides to sacrifice one original part to save another. I really hate destroying things!

 

Engine performance is not often quoted in detail. The British 'Subsidy' lorries all develop a nominal 40hp from about 6.5l displacement. The FWD develops 54bhp at 1400rpm from 6.5l but the Autocars 18bhp at 2000rpm from 2.6l. The FWD weighs nearly four tons and will do about 14mph. The Autocar is only two and will do 26mph which is getting really exciting! The Peerless lorry, which I have never seen run, is supposed to do 18mph at 985rpm. That has to be about the slowest lorry engine ever!

 

Stalling is not too much of a problem because they all have such big flywheels. The downside of this is that gear changes are very slow as the engine revolutions take so long to change and one has often stopped before getting the next gear!

 

I think the British Army expected their drivers to do 100 miles per day for six days each week. The most I have done is 96 and that took 8 1/2 hours. I slept very well that night and the weather had been good that day. I have done 60 miles in continuous heavy rain and that was a bit miserable. The Autocar has no weather protection at all and I was really looking forward to stopping. These old lorries all tend to be pretty heavy and require a degree of brute strength to control, particularly at low speeds. One American road repair foreman is quoted as saying something like 'You need to be a 200 pound man with the strength of a gorilla to drive one but I wouldn't change mine for the world!' He was talking about his FWDs and I completely understand what he meant!

 

Steve

[Great War truck]

Not a lot exciting has been happening for the last few weeks. Tony has had the uneviable task of taking out the studs from the gearbox, like these

 

 

This has been a horrible, laborious task as some of the studs are in pretty bad shape:

 

 

and every now and again something unpleasant happens.

[Great War truck]

Like them breaking off. This (after the required amount of cursing) requires a great deal of time to sort out. The photos should be self explanatory, although i expect Father or Steve will shed some more light on the matter if anybody has a question.

 

 

 

 

 

 

 

 

 

[N.O.S.]

Hmm, I guess those of us with more modern machines are perhaps guilty at times of discarding bits which need a little work simply because we have acess to so much NOS or good s/h components. Perhaps that will change in years to come :sweat:You guys are already there!!

[abn deuce]

Amazing that you were able to get any of those studs out of the top of the case , that one you showed looked so weakened !!! I m thinking since you cant use heat to loosen the studs and you dont want to break them what's your next move ? would you pass an DC electrical current through the stud to try and migrate the iron back to the stud and seperate it from the aluminum case ?

[Minesweeper]

Only two things used to loosen them - heat and Plus Gas. I had it in my mind that there might have been a danger of melting the aluminium casing when using a Propane Torch on the studs, but whilst the steel studs absorbed sufficient heat to do the trick, the aluminium seemed to conduct the heat away fairly quickly and there were no problems. We know from previous experience that really, the best way to move stubborn studs - or bolts is to get them hot.

 

The next job - the transmission brake mountings. The remains of the aluminium ones to be cut out and replaced with a steel fabrication.

 

Tony

[Mark]

Fantastic thread lads, keep it going please.

[LeeEnfield]

Fantastic thread lads, keep it going please.

 

 

 

Agreed. :-D

[Great War truck]

As you will probably remember we have had a problem with the gearbox case. it has two pivot points for the trasmission brake, but as you can see the ali on these is really rotten:

 

 

This ancient aluminium does not weld, and as stopping is quite crucial, we bit the bullet and Father cut it all away:

 

 

 

 

 

which was a *od of a job and took him an age and a lot of knackered tools.

 

Anyway, the plan is to replace the rotten ali altogether with a new steel bracket bolted on to the gearbox.

 

 

 

 

 

It should all work out fine in theory and Greater War truck is doing a fine job, but it is taking a while to do. Still a lot more to be done yet, but he is getting there.

 

Tim (too)

[Great War truck]

We have also just been given an original scuttle for our Dennis. As you can see it is in poor condition, but has some useful parts on it.

 

 

 

 

Tim (too)

[LeeEnfield]

Nice engineering work, there;..........a credit to you all.

[Minesweeper]

Tim's computer is down - the Gearbox Repair is nearly completed and here in Tim's absence are the pictures.

 

There are three steel braces yet to be welded in to the new fabrication - those, plus the main part are to be drilled for bolts to fix this to the Gearbox and there are one or two corners of it to be rounded off.

 

Next job - to strip out another Gearbox in the hope that the "innards" are in better condition so that on re-assembly, we can mix and match to make a good useable Gearbox.

 

Tony

[Sisu]

Unbelievable... Would you guys adopt me? I promise to make you tea everytime you ask.

[gritineye]

Unbelievable... Would you guys adopt me? I promise to make you tea everytime you ask.

 

Praise indeed! and well deserved!

Edited August 1, 2008 by gritineye

[snowtracdave]

A thing of beauty .:bow: