Supplementary memorandum submitted by
Sir Kevin Tebbit KCB CMG, Permanent Under-Secretary of State,
Ministry of Defence
Question 33: Did the Department take that [the
stipulated thermally-stable plastic tubes] out of the specification
when the order was placed?
The thermally stable plastic tubes referred
to relate to the plastic tubes that make up the main body of the
"Main Engine Air Cleaner Cyclone". Each AS90 has one
Cyclone. These tubes are still present and were not removed at
any time from either the design specification or the AS90. The
Cyclone was "thermally stable" for A2 conditions (ie
temperatures below 44C). Although the environmental conditions
on Exercise SAIF SAREEA were not anticipated to be any higher
than A2, actual temperatures reached A1 conditions (ie 49C)
The Department is currently working with the
AS90 Design Authority (BAE SYSTEMS) on a desertisation kit that
will enhance AS90's performance in A1 conditions. One particular
area for this enhancement relates to the Cyclone with manufacture
of the Cyclone's `plastic tubes' from a more thermally stable
material. The Design Authority have now identified a replacement
material that will meet the requirements for operating in A1 conditions.
Questions 169-176 and 211-214: Do you have a contractual
relationship with them [PALL Aerospace]? Have you considered whether
they are in breach of contract [regarding the Challenger 2 filters]?
Do we have any indication whether they would meet the 14 hours
were that the specified minimum performance if you had the correct
skirts and seals fitted to the tank?
The contract for Challenger 2 filters with PALL
Aerospace was for a part number specified by the Challenger 2
Design Authority, Alvis-Vickers Ltd. The Department makes purchases
as and when extra stocks are needed ie `x' quantity of the part
number `y'. This is similar to the way in which the ordinary consumer
buys spare parts for a car; it is not a contract for a special
The life expectancy of the air filters is laid
down in a British Standard (BS)BS1701. This British Standard
gives a life expectancy of 14 hours (a battlefield day) in zero
visibility conditions: that is 1.412 gm/m3 of dust concentration.
The CR2 filters meet this requirement. The filters did not perform
poorlyrather, they were used in conditions that exceeded
the British Standard definition for zero visibility, and therefore,
beyond those for which they were originally designed. However,
they performed tolerably under these conditions, albeit at a higher
rate of usage. Under the circumstances, the Department does not
consider it would be appropriate to seek redress of the contractor.
On the question of whether the filters would
have met the 14 hour standard had the tanks been desertised and
fitted with features such as side skirts and seals, it is not
yet possible to give more than a general assurance. But when the
data from work carried out to trial various desertisation options
has been fully analysed, the Department should be in position
to offer a more precise view on the likely improvements to be
gained from fitting skirts and seals.
Question 230: When was it [the contract for the
Container Handling Rough Terrain (CHRT) system] signed?
CHRT came into service in late 1997 and is made
by SiSu in Sweden. SiSu and Kalmar are part of the same organisation
and for the last four years the 13 CHRT currently in service have
been under warranty to Kalmar. This warranty has now expired and
the Department set up an enabling contract for specific or specialist
repair with Kalmar last month (October 02).
The Royal Electrical and Mechanical Engineers
(REME) provide day to day repairs and general maintenance for
CHRT at Unit level. Where more substantial or specialist repair
is required this is then passed to the Army Base Repair Organisation
(ABRO) who contract out as necessary within the UK or Germany.
This is the same repair chain that operates for the majority of
vehicles or equipment assemblies.
Question 297: I suppose it is a trade-off as to
advantages and benefits [of the new polyester combat outfit given
that airlines were advising passengers to wear natural fibres
to minimise the risk of injury from aircraft fires]?
Fabrics made from 100 per cent cotton, 35 per
cent polyester/65 per cent cotton mix, or 65 per cent polyester/35
per cent cotton mix will all burn at roughly the same rate. The
speed with which these burn depends on the degree of heat applied
and the thickness of the cloth. Polycottons (fabrics containing
a mix of polyester and cotton) are widely used for both civilian
leisure/workwear and military clothing because of their comfort
and durability and they pose no greater or lesser a flammability
risk than clothing made from 100 per cent cotton.
Apart from flame being applied to bare skin,
burns are caused by the penetration of radiant heat through clothing
to the skin and the severity of the burn will depend on the temperature
of the heat challenge and its duration. Protection for a short
period (measured in seconds, not minutes) can only be gained by
providing some form of insulation either by wearing thicker clothing
or, better still, multiple layers that also provide additional
insulation in the form of air gaps. Flame Retardant (FR) coatings
work by forming a charred surface on the fabric which itself becomes
more difficult to burn. FR coatings do not provide any protection
against radiant heat. The latent heat of fusion of polyester (the
heat released as it melts and then solidifies) is not sufficient
to increase burn injury significantly. Medical personnel with
experience of burns treatment in operations do not support the
view that the melt of synthetics onto skin significantly complicates
medical treatment. Burns involving synthetic material result in
a `cleaner' wound than those involving natural fibres.
Operational Analysis has shown that the soldier
on the battlefield faces a minimal risk from purely burn injuries,
the principal damage being from blast and fragmentation. As mentioned
above, protection from burns can be gained through greater insulation
but this will decrease mobility, increase the physiological load
and, when wet, the soldier may face a greater danger from cold
injury as his/her clothing dries using body heat. FR coated clothing
can be more uncomfortable to wear because the coating tends to
stiffen the cloth but it will not protect from radiant heat. A
Defence Clothing programme into flame/fire hazard carried out
by Porton Down three years ago recommended that material of up
to 70 per cent synthetic content could be used in operational
clothing worn by Land Forces.
Sir Kevin Tebbit, KCB, CMG
Permanent Under-Secretary of State
Ministry of Defence