Purpose of this blog

Dmitry Yudo aka Overlord, jack of all trades
David Lister aka Listy, Freelancer and Volunteer

Sunday, May 17, 2015

Fat Fox

 Mid week Quiz: I asked you to identify this turret.

In the early 70's the British developed and introduced into service the FV721 Fox armoured car. At the same time they envisioned a command and liaison utility vehicle based upon the Fox hull. This was the FV722 Vixen. Unlike the Fox they didn't quite get her right. Twenty one years ago she was also a vehicle I helped maintain at a museum, and I have some striking memories of her. The reason why I'm writing this is because a few weeks ago I asked, on my facebook page, for ideas on what to write about. One of the responses was for stuff that wasn't a good idea, and I instantly thought of Vixen.
At first glance the Vixen looks a lot like an attempt to copy the Soviet BDRM-2 armoured car, just from the shape of it. However Vixen's roles were very different, despite similar attributes. Vixen was lightly armoured, maximum armour was 60mm, but that was the skid plate on the bottom of the hull. Her glacis plate was 33.5mm thick, but made of lightweight aluminium alloy. The lightweight armour provided protection against shell splinters and small arms. It also allowed her to be air transportable with three Vixen's fitting inside a C-130 Hercules. She was also capable of amphibious use after a screen was erected, which could be done in two minutes. Her Jaguar 4.2l engine could propel her up to 65 mph on land or 3 mph in water. It's likely she'd actually have gone much faster, as Fox's even with the turret have been clocked at higher speeds, and one Fox without a turret has even been said to have reached 100 mph. She was also fully immune to fungus growth and could operate in temperatures from -40 to +50 degrees centigrade.

Role wise she was to be used by all arms of the British Army. The requirements also called for the fitting of artillery observation or engineering stores, such as an assault boat. The main users were seen to be reconnaissance and Royal Armoured Corps units. Vixen had a crew of a driver and a commander, but had space for two passengers. A radio operator sat in the left hand side of the hull, and a passenger, such as an officer or observer on the right. In the RAC units the passenger wouldn't be carried, and this is where the rot started. Due to having no one on the right hand side, there was no one to operate the periscopes, and so the armoured car was utterly blind to the right due to the placement of the commander's periscopes.

Another sticking point seems to have been ergonomics. The study of ergonomics really took off in the post war period with the Cranfield Institute of Technology at Cranfield University. They took a look at a lathe and worked out what the ideal body shape was for its operator where they can comfortably reach all the controls. They termed this human "Cranfield Man". Cranfield man was 1.35m tall, with shoulder width of 0.61m and arm span of 2.44m...

Well Vixen was assessed for the ergonomics of the vehicle. This included such things as checking to see how much support the seats gave to a soldier's posterior. One thing they noticed was that when the commander rotated his turret he'd be kicking the driver in the shoulder blades constantly. Equally there was an utter lack of headroom, and the report highlighted that as an issue unless a size limit was to be placed on its users.

However that was not the biggest issue with the crew positions. As I said I sat in one of these twenty one years ago, and the position has left a lasting memory; the passenger seats face directly forward. The leg wells are angled 45 degrees towards the centre of the vehicle, whilst your work station, such as the radio's or maps are 45 degrees to the other side. Try positioning yourself in that position now, and you'll see how utterly uncomfortable it is. These positions were not adjustable and locked in armour plate. The idea of driving cross country in such a position is horrific, because even sitting still inside a maintenance bay it was incredibly uncomfortable.

Quiz answer:
I dropped a clanger here. Here's another picture of it:
When I first glanced at the turret (from the other side of the car park) I saw the overhang at the rear of the turret and thought KV-1. When I got closer I thought M3 Lee. However I failed to spot something. An M3 Lee turret doesn't have a loaders hatch. So I'm pretty sure its the turret from a Staghound armoured car.

Image credits:
Cranfield man

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