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Blast  Resistant  Vehicles  –  CF Armoured Fighting Vehicles  –  October 2006

Blast-Resistant  Vehicles  For  Beginners   —   the  Hybrids:
'Belly Plates' under Frames  and  the  Modular Monocoques


Stephen Priestley, Researcher, Canadian American Strategic Review (CASR)
Early 'blast-resistant' vehicles employed a armoured hull, V-shaped to deflect  the blast from landmines. The CF's  RG-31 Nyala APV  follows this pattern.  However, there are other ways to create blast-resistant vehicles and variations on the theme.

No Soft  Underbellies Here – The Pros and Cons of  Full Frames and  Belly Pans

The simplest way  to create a blast-resistant vehicle is to  base this 'new' type on an existing medium truck chassis –  as was done by the Rhodesians for their Crocodiles, the first dedicated mine-resistant troop carriers). There is great allure in  this approach  for designers since much of their work has already been done by the chassis developer. The downside to mounting a blast-resistant  hull on top of a frame (as we saw with the Buffel) is that, while the armour hull may survive the blast of a mine or  IED, the mild steel ladder frame beneath it invariably suffers enough damage to create a 'mobility kill'.

The solution to this problem was to create a V-shaped belly pan to fit  underneath the chassis.  This is not as easy as it sounds.  Two practical problems immediately present themselves. First, the suspension must be free to 'travel' without creating unduly large gaps in the armour. Then there is ground clearance: placing the blast- resistant hull above the frame creates a substantial gap between ground and crew. Moving the belly plate below the chassis protects the frame itself  but at a cost to crew compartment vulnerability – the belly plate being much closer to the ground.

"There's a Good Dog ..." – Giving  Kraus Maffei Wegmann's Dingo a Belly Rub

The German  Dingo  (a contender in the CF APV (Armoured Patrol Vehicle) contest makes a good example of  full-framed and  belly plate-protected blast-resistant vehicle design. KMW got around the ground clearance issue by using a U-shaped (or, more accurately, a truncated V-shape) for its belly plate. The frame is from a Unimog truck. [1] The off-the-self component lent Dingo economy but also gave a degree of grief. The armour plate makes the Dingo quite a bit  heavier than even a fully loaded Unimog. Changes had to be incorporated at a cost to commonality.[2] These were minor bugs, the fixes quite simple, and do not distract from the Dingo.

'Body-on-frame' construction protected  by belly plates might seem fatally flawed beside monocoque hulls. But that's because a crucial element has been left out of our story. Until now, all the designs discussed  have had steel armour. The Dingo crew compartment is steel armour but  its belly is not. The belly pan is a composite panel mounted to the frame with shock absorbers. While steel V-shaped hulls rely entirely on deflecting blast, the Dingo's composite belly plate also deforms under pressure to counter blast energy not deflected or absorbed by the shock-mounts.

Another Southern African Approach  –  Namibia's Modular Monocoque Wolves

Namibia  followed  the South African lead with blast- resistant vehicles but decided it could  build a better mousetrap. Two designs were built in Namibia  – the Wolf and  the related, but smaller, Wer'wolf.  Both are monocoque hulls with a twist. The rear section of the hull is open to allow for modular 'mission kit' pallets.

When equipped with APC-style rear compartments, a Wolf or Wer'wolf  (right) is all but indistinguishable from 'normal' V-hulled  blast-resistant vehicles (one hesitates to call them conventional). The concept is intended to provide maximum mission flexibility on the same hull. [3] For the most part, the vehicles are operated as APCs, complete with a rear shelter.

The unanswered question remains how the modular design stands up to blast – will  the  two  hull components separate under pressure?  Field performance has been impressive. While few Wolf / Wer' wolf  have been made, de- mining is a tough proving ground.  Formal  testing is another matter. Namibia is isolated and resources are limited.  In that  light, creating the Wolf  series is a doubly impressive achievement.

"Pater noster qui ... "  or   Passing the  Blast-Resistant Vehicle  Paternity  Test

Many readers will  have noted  the  more-than-passing resemblance between the Namibian Wolf series and the 6x6 Buffalo route-opening vehicle now deploying  with the CF  to Afghanistan.  CASR  will survey the current major blast-resistant vehicles by type. In that series we will trace the sometimes complex parentages of designs like the Buffalo – and the Wolf  itself – amongst others.
[1] Early model Dingos (also called ATF1s, from Allschutz Transport Fahrzeug or All-protected Transport Vehicle) used a Unimog U100 L chassis.  This proved too weak and prone to frame flexing. The Dingo 1 (confusingly, an ATF2) had a stiffer U1150 L chassis. The variant offered to Canada was the improved Dingo 2 (ATF3) using the largest of  UHN (Unimog Hochmobil = highly mobile) frames, the U5000.
[2] The standard Unimog suspension had to be strengthened due to higher weight and to be made less 'springy' – soldiers had made complaints of  motion sickness.
[3] In an old Wer'wolf  Mk II brochure, the Namibian Ministry of  Defence (owners of manufacture, WMF) offered APC, logistics, riot control, tanker, and ambulance shelter modules and open mounts for 23mm AA guns, recovery cranes, and rocket launchers. The Wolf  (HEC modified ) is used by MgM for humanitarian de-mining.
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In Detail Review – 'Add-ons' and a Case for Blast-Resistant Support


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