The following article on German military pile drivers was originally published in Tactical and Technical Trends, No. 46, May 1, 1944. [DISCLAIMER: The following text is taken from the U.S. War Department publication Tactical and Technical Trends. As with all wartime intelligence information, data may be incomplete or inaccurate. No attempt has been made to update or correct the text. Any views or opinions expressed do not necessarily represent those of the website.]

GERMAN FIELD PILE-DRIVING FRAME The information in this article together with the report about German Pile Drivers, contained in article No. 9 which follows, present a rather detailed account of this particular type of German engineering equipment used in bridge and other similar construction. The German field pile-driving frame 1939 model, Feldrammgerüst 39, is used for pile driving in the construction of improvised bridges up to 24 tons capacity. It is carried in trucks in the light engineer column and in bridging column B.[1] a. Description The equipment consists of a guide mast with a double block at the top, supported on a base by two back stays. For pile driving from the ground the frame is mounted on four wheels, which are steered by iron bars; these wheels are replaced by beams when pile driving is carried out from a raft. A two-drum hand winch serves to raise and lower the pile driver. For erection of the guide mast a jury mast is provided. The guide mast can be built up to heights of 13, 20, 26 and 33 feet. The back stays can be of either single or double length, single length stays being used for 13 and 20 yard masts, and double length stays for 26 and 33 yards. The following can be operated on the frame: three-piece hand operated monkey, 440 lbs; compressed air pile drivers, 360 ft/lbs or 1,440 ft/lbs; diesel pile drivers, 992 lbs or 1,323 lbs. b. Erection (1) On Ground The base consists of two main parallel members with two wing legs pivoted to the forward ends of the main members. These wing legs are swung outwards and joined up to the rear ends of the main members by a connecting joist. Four roller type wheels, which are fitted in housings at the ends of the wing legs, can be steered individually by tommy bars.[2] The mast is built up on the ground to the required height out of a 13-foot base section, a 13-foot center section and a 6 and one-half foot top section. The double block can be fixed to the top of any of the sections. The foot of the base section is then pinned between the forward ends of the main base members. The back stays are built up of either a single length or two lengths according to the proposed height of the mast. Each length of stay is provided with a screw-adjustable lug at one end only, so that the lengths can be bolted together. If only one length of stay is required a fixed housing containing a rotating lug is bolted on to the free end. The side stays are then pinned to the mast at the appropriate points. The jury mast is then placed in the special sockets provided for it, immediately behind the mast securing pin, at the front end of the main members of the base. Six-hundred and sixty pounds of kentledge[3] is placed at each rear outer corner of the base and 40 sandbags are included with the accessories for additional weight. The cables from the two drums are then drawn out; the cable from the forward drum is passed over the jury mast pulley and one pulley of the mast head-block and made fast to a cross-bracing at the bottom of the mast; the cable from the rear drum is passed over the second head block pulley only, and also made fast to the cross-bracing at the foot of the mast. After attaching the side guys to the head of the mast, erection can be commenced, with four men on the winch handles, one man on each back stay and each side guy. Drive to the forward drum is effected by a sliding pinion the changing lever being accurately pinned before starting the winding. During the winding the ratchet must always be engaged. As soon as the erection cable clears the pulley of the jury mast, the mast is removed. During raising, the back stays are guided on the wing legs of the base and finally pinned into position. Once the back stays have been fixed, the cable from the forward drum is slackened off and two pulleys are fixed in a sheave bracket at the foot of the mast. The mast is then squared up by rotating the back stays on their screw-adjusting lugs. (2) On Water For pile driving in water the frame can be built up on any of the following: 4-ton raft, B column equipment 8-ton single raft, B column equipment 4-ton raft, C column equipment[4] or any suitable improvised raft. On the 8-ton single B raft, the frame can be erected either to operate over the side, between the two pontoon piers, or at one end. For side operations the base is screwed down to the full width cross-beams between the inner ribands and to one short beam located between the inner and the outer ribands. For end operation the platform is fixed to one cross-beam between the inner ribands and to the short beam located approximately 4 inches from the edge of the end chess.[5] Erection then follows as previously described. No kentledge is required. [1] Bridging column B is a German bridging unit consisting of Headquarters, 2 platoons of pontoon and trestle equipment and 1 platoon of supplementry equipment. This is usually attached to the engineer battalion in infantry, motorized and mountain divisions. [2] Extension levers [3] Scrap-iron weights [4] Bridging column C is a unit similar to bridging column B, but carries older type of bridging and pontoon equipment. This unit is obsolete and is being replaced by the bridging column B. [5] Deck plank or floor boards of a floating bridge

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