How to make a slit trench

Essexx Constabulary, Head Quarters.

To All Superintendents - Appended below are instructions regarding the marking of "Slit Trenches". This information is to be passed to all Police personnel so that in the event of an invasion all will know how; to make such a trench at any Police Station if required.

Narrow trenches, known as slit trenches, have been found by experience to give a high degree of protection from Artillery fire and dive-bombing attack, to which we may be subjected in the event of invasion. All, therefore, who can, should dig such trenches when the time comes, and meanwhile, make preparation for doing so.

Slit trenches should be as narrow as possible, about 2 feet wide and about 3 feet deep. 2 feet 6 inches should be allowed for each person to be accommodated. They should be at least 15 feet from the nearest building.

The earth should be piled up either side as regularly as possible, 1 foot 6 inches high. Trenches are improved by being lined with timber and stakes, old doors, old coated iron sheets or any scrap material available, but new material cannot be issued for the purpose.

A light cover of similar materials, as protection against rain and gas spray, would also be an improvement, but earth should not be piled on the cover. It will help to keep the trench if the bottom is slightly sloped and a sump-pit is dug at the lower end and filled with stones and pieces of old bricks. For the same purpose, duck-boards, made of odd pieces of wood, will be found useful.

It is not, however, desirable to dig slit trenches a long time before they are likely to be used, as they may get wet and fall in after a while, but trenches should be marked out now and, unless the soil drains very badly, a shallow excavation, about a foot deep, should be dug before, say, the middle of April in order to reduce the amount of work to be done at the last moment.

Care should be taken to have a garden spade available when required.