Mark IV 007 Build

[Steve Stuart]

Following the last outing of the Mark IV at Reading I have been concerned about the internal temperature of the Tank and some of the electrical units. So a trip to Maplins and a pair of quiet running 40mm 12v Fans purchased. I have mounted these onto a frame that sits behind the Radiator Vent. I hope that this will now draw warm air out of the Tank, especially from the Smoker which is located 5" in front of the Radiator Vent, we shall see
However, this arrangement does show quite graphically that the upward facing vents blast the exhaust fumes upwards. This would be a great boon for any Soldiers following in the shelter of the Tank as it would have stopped them being gassed by Carbon Monoxide from their protector, which downward exhausts would certainly be doing
Perhaps another example of how making a functional model might help a practical understanding of the real circumstance?
Steve

[Stephen White]

Steve, how cleverly realistic! The crews of the Mk IVs did suffer from gross overheating and carbon monoxide poisoning and it seems you've captured it perfectly. I recall that infamous film of a crew trying to get out after a demonstration to the King at Thetford, clearly showing all the signs of carbon monoxide and heat stress.

Looking forward to seeing her again in Oct with some of the other Mk IVs.

All the best.

Stephen

[Chris Hall]

Steve -

Perhaps that explains why the only tanks that seem to have the downward-pointing radiator vents are the 100 built by Coventry Ordnance !

It's a bit worrying that overheating could be a problem, but I know you've put some extra stuff inside 'Bloodstone'. Personally, I'm not fitting a Smoker, so we'll see if that's the root of the issue. Does the top hatch not provide sufficient heat escape ?

I'm with Stephen, though, that these builds are bringing out a lot of history. Now I need to do some research into combined arms tactics, to find out how closely the infantry followed the tanks .......

All the best,

Chris

[Steve Stuart]

Perhaps I am being overly concerned, but on a hot day in the sun, a Tank can get quite warm so anything that helps to keep things cool is good.
The smoker does obviously get warm and I do like 'improving things' particularly if they can serve a couple of purposes. The second of which is to create a good cloud of smoke behind the Tank.
Steve

[Steve Stuart]

My trip to Bovington today resulted in a photo I have not achieved before, a shot of the detail of the roof of the Cab.

Mark IV Cab Roof

Given that I had to sneek a way to get some extra height, I feel it must be a rare one!
I hope it will be useful!
Steve

[Steve Stuart]

There has been a lot of research and thinking on the issue of the unditching beam and I am getting there. I will be checking with Chris to make sure that my bolting pattern for the top and bottom steel plates is not too wrong?
I am basing my beam on Lincoln's Flirt, Brussel's Lodestar and Bovington's Mark V.

Mark V Unditching Beam

I have made measurements as best as I can given that it is hard to get at the beams, as I didn't want irate curators chasing me, but amalgamating everything has given me the confidence to commission the furniture making Husband of my wife's friend to make me a beam or two and Rapid Metals have cut sheet steel to the right size for the plates.
Once I have Mr Hall's expert eye cast over my sketches, I will post some photos of the beam coming together.
Steve

[Chris Hall]

Once I have Mr Hall's expert eye cast over my sketches, I will post some photos of the beam coming together.

Definition of an expert: 'X' is a has-been, and 'spurt' is a drip under pressure .....

[Steve Stuart]

The beams are now coming together, the material now having arrived. Michael, a furniture maker, made me up the wood and I ordered up the steel plate cut to accurate width, but rough length.

Unditching Beams

The end bands were bent round a former and then the ends were brazed together to complete the loop. They are going to secured with an 8BA rod and nuts through the middle. The bolting pattern is shown in my rough sketch below.

Bolt Pattern

The plates are to be secured by 6BA rod and nuts drilled through from top to bottom.
The attachment points for the shackles are still being thought about!
Steve

[Daniel Scholefield]

Wow, the kit beam is a nice piece of wood but that looks much better, the grain looks for more to 'scale'. Nice work with banding too.

[Steve Stuart]

Michael chose some wood that simulates the sort of 'robust' timber that might expect to have been used. He also used a blade that mimics the sort of coarse saw cut that a circular saw produces, I was very impressed by his getting what was needed!
The Banding has interesting to bend around a former, not quite straight forward. I was pleased how the join came together when brazed. The next project is the attachment points for the chains,
Steve

[Steve Stuart]

The first beam has plates attached with bolts drilled through the beam. I have yet to attach the bands, the question being should they be riveted or bolted?

Unditching Beam

Unditching Beam

The other decision is, do the chain attachment points bolt to the top or the bottom of the beam? Photos and other sources show either option and it may have been at the whim of the fitters or crew of the tank concerned.
All I can say is that I am pleased how it is coming together. The combination of wood and metal has turned it into some thing substantial and it is possible to see its strength which would be necessary when it is used to drag a tank out of the mire of mud.
Steve

[Steve Stuart]

Name and Number
With a certain amount of help from various people and organisations (Dave Thornhill, John Hill, Stalite) I have got some stencils made and I have now christened my Mark IV with its number and name, B27; Bloodstone.

B27

Bloodstone

There are no photos of B27, so my interpretation is based on the B Battalion tanks whose pictures were taken by Germans after they were knocked out at Fontaine-Notre-Dame. Dave helped greatly by providing the insight in to the form of the sign written 'type face' used. Stalite of Exeter produced the stencils with a very straight forward positive approach compared to others who could not even produce a satisfactory sharp intake of breath! I would like to thank John for his recommendation.
Steve

[John Hill]

A very realistic result Steve, It's always a game of chance when recommending something, But I have always been pleased with Stalite ( usual disclaimer ). They did the stencils for the Comet and as you say they are straight forward to deal with, and affordable.

regards John

[Steve Stuart]

Ditching Rails

Can you spot the difference? I find it intriguing how we all find details that need to be sorted out while others find something else! Another photo to help guide your observations.

Flirt at Lincoln

[Chris Hall]

It helps if you look around for pictures of the original Armortek parts Suffice to say, though, that Steve has forsaken the concept of 'stand off' in favour of microscopic authenticity !

As ever, I'm in awe of his skills, and grateful for his help on my forthcoming issues with the Female sponsons.

Chris