1.

PART I

1. OBJECT OF TRIALS

To ramp a sea wall in the initial assault by explosive means in such a mnner that it can be climbed by a tank. For a typical section of the wall See Plate 1.

2. METHOD

(a) Placing against the wall a Standard Production Model Goat Mk III. carrying a 1600 lb. Inverted "U" charge of explosive 852 and firing it without any exposure of personnel to produce a branch at right angles to the line of the wall.

(b) Placing a 1764 lb. staggered charge by hand with the minimum exposure of personnel to produce a diagonal breach in the wall.

3. SUMMARY OF RESULTS

Both methods proved successful. For details see Part II para 1 .

4. CONCLUSIONS

From an analysis of those and previous results reported in our 1st and 2nd Interim Reports and the report on "Ramping sea walls for passage of Wheeled Vehicles" the following conclusions can be drawn:-

(a) One method of breaching a sea wall which does not involve the exposure of personnel is by the use of one or more A.V.R.E. firing their petards. An 8-ft. high sea wall was breached by firing 17 rounds - an operation which would take one A.V.R.E. 6 mins. or 2 A.V.R.E. 3 mins. to perform. For higher walls it my be advisable first to place a fascine in front of the wall and than to fire over the top of it. Such a fascine should not be greater than 6-ft. in diameter.

(b) Another satisfactory method which also does not involve the exposure of any personnel consists of placing a 1600 lb, Charge in the form of an inverted "U" against the wall by means of a Goat. This produced a successful breach in a 10-ft. high wall in approximately 4 mins.

(c) Another satisfactory method is to place a 1764 ib. staggered charge by hand. This operation was carried out by the crews of 2 A.V.R.E. against a 10-ft. high wall in 7 minutes. The charge was made up in 40 lb. approx. packs and produced a successful diagonal ramp.

(d) All personnel should be undercover when the charges detonate owing to the danger from fragments of the wall which fly side- ways and backwards.

(e) An armoured bulldozer or tankdozor is useful for cleaning up breaches which are only partially successful and for easing the slope of the ramp produced for later passage of wheeled traffic.

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