restoration of a valentine MK5 tank started

[jdmcm]

Andrew

 

The engine looks like a work of art, was it difficult to source a starting motor or did you rebuild the original?

 

Regards

John

[Andrew Rowe]

Hi John, greetings from "Down Under", the starter motor is a replacement MT39 brand new, made in Donald Trumps home town of Mexico!

This has a reduction gear for a faster turning speed and electric solenoid for engaging with the ring gear. The horsepower and torque are greater also than an original. We did have to recut the 11 tooth gear from 56mm down to 52mm so it engages properly with the 103 tooth ring gear. It appears that the gear is induction hardened so we feel the hardness of the gear was not effected. This option was taken with the starter motor for reliability, as you know how fun it is changing a starter motor in the bowls of a Tank , Cheers Andrew.

[Andrew Rowe]

Sorting through more original control rods and end clevises. Mainly 3/8" BSF with some L/H and R/H turnbuckles for making the adjustments.Luckily I have a set of 1/4" up 1/2 " BSF Left hand taps and dies, which does make life easier. I think I added up the other day nearly 42m of rod of this type in the floor . Cheers from The Tank Factory. Happy birthday Adrian B , 50 !:-).

[Andrew Rowe]

We are still sorting control rods and brackets at the moment , although most have now all been blasted and painted. The first four pictures show the steering clutch and brake control rods now properly sorted, and ready for install. The next couple of pictures show the air cleaners we have been working on. These are original housings, oil bath type , but we are going to run dry type air cleaners for better efficiency and performance for the engine. The modification is done in such a way that they can be easily converted back to the original elements, if that needed to be done. The last 3 pictures show the fuel cap setup that I have been playing with. I had to get some new fuel caps cast up in bronze and I have machined the rough cast back and cut the new thread ( 16tpi ). The fuel caps are always missing when I have found old fuel tanks, so I have managed to borrow an original for the casting of my new ones. Cheers from The Tank Factory.

[Andrew Rowe]

Next in line is the gear change shifter. This consists of 4 major sections. The front unit is the gear shifter housing that contains the gate for the gears, 5 forward and one reverse. Then there is a long shaft ( 1 &1/4 " dia. )that runs to the middle bulkhead through some bearing housing supports, then another universal joint, there being 3 of these in total along the shifting tube. Down the back, at the business end there are a couple of supports for the gate that connects to the Spicer gearbox. There are provisions for adjusting the gate to the gearbox for alignment and to make the gearbox gears mesh and perform correctly. Cheers from The Tank Factory.

[Andrew Rowe]

Looking at the gearbox shifter gate the other day, something did not look right , so it looked like we had rebuilt a MK3 one, which is still 5 speed plus reverse, but with a slightly different layout, a trap for young players! The first two pictures show what I am talking about. MK3 uses a Meadows type 22 "crash "gearbox and the MK5 uses the American Spicer synchromesh box. The next 3 pics show the steering controls being assembled with their new bearings, etc. There will be 1/2" BS chain that will wrap around the "pulleys" at the end of the actuating shafts. These will transmit drive backwards and forwards to the rear of the Tank when the steering levers are being used, it will become clearer as the whole assemble comes together. The last pic show the steering rod support pads that go underneath the fuel tank and battery tray either side of the Tank in the rear engine compartment. These had to be made new, as are always rotted away. Cheers from The Tank Factory.

[Andrew Rowe]

Running along side the Tank rebuild, the electrical/ signals department has reported back with updated progress on the restoration of the 19 set that will fit inside the Turret. Just to give you a "Brief " background to the type of radio we are using.

The WS No. 19 was developed from a British military specification issued in 1937. This called for a radio with a short- wave transmitter and receiver ( for regimental and squadron communications ) , plus a VHF transmitter and receiver for short-range inter Tank communications. In addition it was required to have an intercom for the crew communication within the Tank. The British PYE company was awarded a contract and began production of the No.19 set early in 1941. An improved MK2 version was produced from March the same year and during WW2 No.19 sets were manufactured in Australia, Canada and the United States. So , this set being 70 years old needed an overhaul to make it operational again.

The radio consists of two modules, a power supply unit and a radio transceiver/ intercom module.

Power Supply: This unit contains a 12-volt dynamotor ( also known as a "rotary transformer" ), which produces high- tension D.C. voltages of 275v and 500v , to operate the radio and intercom. It also houses fuses and filter capacitors.

The commutators and brushes of the dynamotor required cleaning and the rotor bearings needed to be repacked with grease. All the old capacitors no longer met specs and were replaced with more efficient and reliable modern capacitors. In particular the high -tension electrolytic capacitors were replaced with modern non-electrolytic motor-start capacitors..............you still with me!

These use a polypropylene dielectric , which provides almost infinite insulation resistance and much improved efficiency and reliability. During WW2 , the failure of electrolytic capacitors in 19 set power supplies was a major problem and there are reports that on one occasion a large consignment of higher quality replacement capacitors were flown from the USA to North Africa to repair all Tank radios in the western Desert.

Transceiver Module: In overhauling the 19 set transceiver module, all capacitors also needed replacing -a total of 25 capacitors. Some of these were low voltage types where modern mylar-dielectric capacitors could be used as replacements. Higher voltage types were replaced with polyester , polystyrene , or ceramic capacitors. Unlike 70 years ago there are many capacitor options available today and so capacitor types most appropriate to the particular circuit function can be selected.........and you thought we were dummies!

Other components that needed replacing, were resistors. The original resistors were carbon - composition types. These were made of carbon powder mixed with an electrically inert material such as talcum powder , and sealed with resin. Even when new , these resistors had a resistance tolerance of + or - 20%. After 70+ years their accuracy is now sometimes greater than 100% off. Composition resistors are no longer available , so new carbon- film or metal film resistors were used as replacements. These have an accuracy of 5% and 1 % respectively. A total of 35 resistors were replaced in the radio.

Wiring: much of the internal wiring of the radio had used natural rubber insulation, which had deteriorated over time. Wire with cracked and crumbling insulation was replaced with modern Teflon - coated wire. other wiring in the radio was treated with an epoxy sealer.

After restoration, the radio's functions were tested and the receiver was realigned. The parameters tested were transmitter output power, receiver audio output, and sensitivity and signal / noise ratio. The intercom gain was measured and the power supplies voltages and ripple waveform checked.

Now after a total overhaul of the No.19 MKII Wireless set, we have a communication system better than it was in WWII. Testament to this is the fact it now puts out 10 watts of RF power on CW instead of the 7 watts it put out when it was new! So, I think it should still be going in another 70 years:-)

Attached are pics of the set and the original components taken out and new replacement components and the testing of the set. We still have to add front protective grills and the mounting for inside the Turret Busslle. Cheers from the Tank Factory.

[Grasshopper]

Ah, the veritable Bird-Watt meter! We used those at work when as part of diagnosing faults with on-train railway radios.

[draganm]

very cool. Same things are done now with vacuum tube radios and amplifiers from the 50's, but in those cases all the specs are known and you just buy the kit. the choices you have in parts is truly overwhelming, I've done similar with 1990's electronics and you can spend hours looking at capacitor specs. Can't imagine how much time it took to cross reference parts from the 40's.

 

This is very likely the first time someone has done this with a WW2 British Tank Radio transmitter however, nice job.

[g0ozs]

Really nice job of the WS19 My then near neighbour Arthur Stevens (M3FFU) now a silent key did a full rebuild of his WS19 in the early 2000s and this brings back memories (despite the rather recent callsign, Arthur started at Marconi's Chelmsford works in 1946 and retired as a senior engineer in the mid 1990s so he really knew his way around wartime electronics!)

 

Capacitors were a pain well into the 1970s - when I started work designing telecommunications equipment in 1987 I was warned off using tantalum capacitors by the reliability engineers where I worked, and true to their predictions the tantalum capacitors are the main cause of failure in "modern" clansman sets of the 1970s that cross my bench today

 

Iain

73 de G0OZS

Edited August 4, 2016 by g0ozs
Correct Arthur's callsign

[Chris Suslowicz]

Ah! A.G.I. = Aeronautical & General Instrument Co. (Still going strong today, mainly in the Defence market.)

 

Incidentally, you may be on the other side of the planet from me, but if you'd like a watch holder to cover up the three screw holes in the set, I can pop one in the post to you. :-)

 

Chris.

[eddy8men]

Excellent work and very informative for those of us mucking about trying to get old 19sets working. I changed the old mechanical vibrator on my PSU for a more reliable electronic one or should I say I sent the old unit off to someone more intelligent than myself and they did the work for me for £15. When I get back from holiday I can dig out the contact details for anyone that's interested

[Packhow75]

Excellent work and very informative for those of us mucking about trying to get old 19sets working. I changed the old mechanical vibrator on my PSU for a more reliable electronic one or should I say I sent the old unit off to someone more intelligent than myself and they did the work for me for £15. When I get back from holiday I can dig out the contact details for anyone that's interested

 

Rick

 

That would be excellent thanks.

 

 

Cheers

 

Tim

[Top Roller]

Hi Andrew

 

Excellent project, with some really good pictures. I am currently rebuilding a spicer gearbox but could use some of the tech information on setting everything back up properly. Could you give me a steer where I could access the information please?

[Andrew Rowe]

Hi "Top roller" , we have learnt what we know through pulling down and rebuilding several of these spicer boxes. The parts manual also indicates what parts are required and quantities needed, have not got any rebuild manual as such , just plenty of experience, Cheers Andrew.

[Andrew Rowe]

A few more parts to the puzzle, we have the electrical diagram/ with Aux. fuel tank release lever. Next is the rear battery tray, that will be installed but not used for batteries, as we will run 2 x 12volts up front. Originally they used 4 x 6 volt batteries wired up to give 12 and 24volt. The last couple of pics show the machete brackets that go under the sloping drivers plate for stowage and also the front diver's floor drain valve. Cheers from The Tank Factory.

[Andrew Rowe]

For the Drivers controls we have the acc. pedal / clutch and brake pedals. The last couple of pics show the rear brake connections for the steering clutches and brake control rods, and then the last pic shows the aux. foot brake flexi-able cables that run from the middle bulkhead forward to the drivers controls. So , there are basically 3 lots of rods either side of the driver that run to the back of the Tank for controlling movement. There are also 3 more combinations of rods for ; main engine clutch / acc. and engine stop also. Emergency engine shut down is located at middle bulkhead, left hand side. Cheers from The Tank Factory.

[Andrew Rowe]

Here we show the driver's steering lever main supports. The next pic shows the installation of these controls going into the front drivers compartment. The last pic we are trail fitting the fuel tank and conduit to make sure nothing interferes with each other, which is critical, because when the engine goes in, it is a perfect fit and nothing wants to be out of place, so do it once , do it right , not sure where the vacuum cleaner bolts to though? Cheers from The Tank Factory.

[Top Roller]

Hi "Top roller" , we have learnt what we know through pulling down and rebuilding several of these spicer boxes. The parts manual also indicates what parts are required and quantities needed, have not got any rebuild manual as such , just plenty of experience, Cheers Andrew.

 

Hi Andrew

 

Understood - its clear you have that in spades - would it be ok to contact you with a wish list for some spares?

 

Jon

[Andrew Rowe]

Showing today are the oil pipe lines and the oil tank. The engine runs a "dry sump " , so has this tank for it's fluid. The oil on a Mk5 also runs through a 5-row oil cooler that will run across the width of the Tank above the gear box. This part will go in after engine and fan bulkhead. The 3rd pic shows the engine water drain , that comes across the front of the engine, through the middle bulkhead and through a hole in the floor to drain. Along side and above it we have the commanders engine shutdown lever and knob. This is connected also to the drivers shut down lever, through clevis's that have long slots in them, so either can shut down without effecting each other. The last series of pictures we can see all steering controls together and their associated rods through to the rear engine compartment, and the "business" end. Cheers from The Tank Factory.

[Enigma]

The progress is astonishing.

Looking forward to footage of the tank driving under its own power.

[Andrew Rowe]

Shown are a few more pictures of the remote gear change shaft , that runs the length of the Tank. There are 4 round steel

housings that are held in bronze castings along it's length. Inside these steel cylinders are 2 x sets of bronze rings that hold 22 x 5/16th steel balls each ,that form a cage that the 1&1/4" shaft slides and rotates on to transmit the movements required for changing the gearbox to the selected gear. The last 2 pictures we are test fitting the engine. This requires about a 20 degree angle , the front being lower when it is lowered in and moved forward to rest on the front engine mount. Both steering levers have to be fully back to allow enough space for the steering clutches to be moved back against the heli-hub units to allow a gap of about 5mm each side for the bevel box to be lowered in as the engine is moving forward. It just clears the rear conduit by about 10mm as this happens. The bevel box mounts need to be in position on the bevel box as it is lowered, as once it passes down pass the clutch units you cannot get them in! We have found that we are 3mm too high on these mounts, so I will mill that off the bottom to bring the output flanges in line with the clutch units. Just happened to measure the centre of the fan hub from the inside wall of the Tank, and each side measures in exactly the same,@ 309mm!

Cheers from The Tank Factory.

[andypugh]

The machine seems to be engineered in a manner that makes you wonder if the designer ever considered that somebody might be shooting at it.

It seems to be designed for long-term super-reliability rather than any level of damage-robustness.

[Andrew Rowe]

These Valentines were in used right up until 1960! and the odd part were still in Govt. stores in the late 70's early 80's.

I have heard stories of things like steering clutches being specially ordered from the original manufactures in the 1950's to keep our ones going when the NZ Army decided to form Armoured Brigades for CMT ( Compulsory Military Training )Cheers Andrew.

[Andrew Rowe]

Work continues on laying all the wires through the conduits. At first we thought we could prefab some of the looms before install, but this was not to be the case, as in order to fit them in the Tank, sections have to be unscrewed and moved into position and then done up again. Sometimes it can be a painful process of putting conduit in and then doing everything up , only to find that you have to take them back out because there needs to be a few alterations , as the tubes interfere with more parts that get installed later on, so it is all about knowing the next parts and processes and what effects each other. Sounds confusing?:nut: We are using standard automotive wire of different gauges inside the conduits as very little is actually seen. All ends are soldered and heat shrink sleeves used to insulate the joints. Also the main battery cable feeder conduits we have done outside of the Tank before installation. The last pic shows the rear bulkhead terminal block wires to engine generator (24V ) and cold starting wiring loom.Cheers from The Tank Factory.