CO129-589-4 Air raid precautions- supply of equipment 1-11-1940 - 24-1-1941 — Page 14

General Lucas.

BE

13

SCALET

HONG KONG A.R.P.

I have studied this, and without attempting a comprehensive

commentary, set out some points which occur to me.

(1) Questions of expense I must leave entirely apart, since I have no

information what you can get for your money in Hong Kong. The highest

mentioned

priced unit is

is the $15 tunnel or trench: you don't get much for 18s./9d. in

this country: so that, whatever values are in Hong Kong, it must I think be

a primitive form of defence. Equally, we have no knowledge as to the materials readily available.

(2) Dispersal, if it carries the citizens out of the bombed zone, is of

course a first rate remedy. Experience in London shows that, although

there are many targets, nevertheless intensity of bombing drops as you

proceed outwards radially from London Bridge. Casualties occur in strict

proportion to the weight of bombing multiplied by the density of the

population, so that if density can be increased where bombing is less in-

tense and be decreased where it is most so, casualties must be saved.

grade shelter in dense areas near to the probable focus of bombing is a

doubtful proposition. Hong Kong probably has its equivalent of London

Bridge.

disintegrated

Low

(3) The description "Concrete pens" does not give much of an idea of what

is meant. Our experience is that overground structures have weaknesses

which are not apparent.

by earth

transmitted shock and the roof slabs brought down on the occupants unless

the roofs are well tied to the walls.

Their walls are liable to be

Surface or near surface trenches are similarly vulnerable to lateral

crushing from earth movement from bombs at considerable distances.

Experience of shelling gives no conception of the magnitude of thes

movement. There have been heavy casualties amongst service personnel

ductile

(stul or sheltering in such trenches. A lining of some flexible substance is

important: precast units make bad linings.

RIC.)

(4)

One important fact should not be lost sight of. If active defence is

successful, day raiding may, as in 1940 in the United Kingdom, become too

costly, so that night bombing may be adopted.

Given serious and frequent