CO129-589-4 Air raid precautions- supply of equipment 1-11-1940 - 24-1-1941 — Page 31

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Concrete Pens.

Tunnels.

These are above-ground concrete structures and will

resist blast and splinters from 500lb. high explosive

bombs falling 50 feet away. Each pen accommodatos 120

people, and at present 12 pons have been erected, giving

accommodation to approximately 1,440 people at a cost of

$7.80 per head.

The supply of blocks for the construction of the se

pons is limited, due to the lack of plant and to the fact

that only three firms would undertake to produce on a

mass-production scale.

At present our commitment amounts to $94; 200 and

this sum was provided out of the first million dollars,

but a further $507,000 has now been asked for in order to

extend protection to the central and western districts

to house approximately 66,400 people.

The advantage of pens is their comparative cheapness

and the case with which they can be erected. The money

expended on the production of concrete blocks will be

largely recoverable as they have been made in sizes

suitable for future building purposes.

It is proposed to accommodate in this way approx-

imately 213,930 people, and it will take approximately

12 months to erect at a cost of $1,657,710.

are:

The advantages of tunnels over all other systems

(a) Complete protection

(b) Accessibility

(c) Comfort.

Accessibility is important, especially in the

central and western districts, where there are few

spaces for the erection of concrete pens, construction

of trenches, or Dispersal Areas available, and the only

real solution to this problem is the construction of

tunnels.