54. General

The three types of standard German delay fuzes described in this section were designed to be used with concealed charges which would be detonated sometime after an area had been given up to opposing forces. In World War II these fuzes were found attached to charges under bridge spans, in important builings in cities and towns, and in ammuni-tion dumps. The fuze could be used by saboteurs to demolitish strategically important installations and structures after the saboteurs had time to get away. These fuzes func-tion either by a clockwork type of mechanism or by chemical action. They are all similar in that the mechanism is housed in a bakelite or plastic container. The lapse between the time the fuze is armed and the time the charge is exploded varies from 1 minute to 167 days.

55. Chemical-Mechanical Time Delay Fuze 41W (Chemisch-Mechanischer Zeitzün-der 41W; C.M.Z. 41W)

a. Description. The chemical-mechanical time delay fuze 41 (fig. 55) is a delay, chemical, handset fuze containing a spring-loaded striker with a corrosiveneck release. It is 5 1/2 inches long and 1 1/4 inches in diameter. The fuze consists of a cylindrical black bakelite case with a threaded arming cap and a combination brass percussion-cap-and-detonator holder screwed into the base of the fuze. Inside the upper part of the fuze is a glass am-poule containing acid. The glass ampoule rests on a bakelite, striker-retaining disk having four seep holes which pass through to the reaction chamber below. The spring-loaded striker is made of white metal and is fastened to the striker-retaining disk by a small set screw. Only the upper portion of the striker shaft is exposed to the chemical reaction by the acid after it seeps the reaction chamber. All other parts of the striker are protected form the acid by rubber washers.

b. Employment. This fuze is used for the delayed detonation of large charges in areas abandoned to an opposing force.

c. Functioning. The acid corrodes the exposed part of the striker shaft in the reaction chamber until the striker shaft breaks, releasing the spring-loaded striker against the percussion cap. The higher the temperatur the more rapid the chemical reaction on the striker shaft. The chemical reaction ceases below -40° F, but resume as soon as the temperature rises above that point. The following temperatures and the corresponding delay period until chemical reaction completely corrodes the striker shaft are given as a guide:

68° F

3 to 5 1/4 days

32° F

21 to 31 days

–

31° F

96 to 167 days

d. Installing and Arming.

(1)

Remove the threaded arming cap and insert the glass ampoule of chemical, neck down, into the top of the fuze.

(2)

Screw on the arming cap until the top is felt to contact the top of the glass ampoule.

(3)

Insert a detonator into the base of the fuze and screws the fuze into the charge.

(4)

Screw the arming cap of the fuze on further until the glass ampoule breaks, causing the acid to seep down into the reaction chamber. The fuze is now functioning, but it is safe to handle for at least 5 hours.

e. Neutralizing. If at all possible, any charge with this fuze should be blown in place. There is no safety device on this fuze, and it is impossible to known at what moment the striker shaft may break under the corrosive action of the acid. If it necessary to neutrali-ze the fuze, one man only should carefully unscrew it from the charge and remove the detonator.

f. Packing. The fuzes, with the ampoules but without the detonator, are packed eight to a cardboard cartion.

Figure 55. Chemical-mechanical time delay fuze 41W.