Rubber Fabrication Plant Targets (Hanover)

Taken, from:
The U.S. Strategic Bombing Survey
"European Theater of Operations"
Second Edition January 1947

Rubber Fabrication Plant Targets

From synthetic and reclaimed crude rubber, 278 plants manufactured rubber goods of all sorts from tires and tubes to rubber boots and fruit jar rings. Of these, (!) one of the largest were Continental Rubber at Hannover (...). In 1943, Continental accounted for 45 to 55 percent of the tire production of Germany (...); (...), made ~5 percent of Germany's tires. In addition, these plants produced large quantities of footwear and other rubber goods.

Consumption Of Crude And Synthetic Rubber In German Fabricating Plants

Plant: Continental-Hannover
Consumption of Crude and Synthetic Rubber, 1943, Tons: 36000
Approximate Percent of Total Consumption: 40
Products: Tires, tubes, mechanicals

. The manufacture of tires is a complicated process involving the compounding, mixing, and milling of Buna and reclaimed rubbers with chemicals, carbon black, and oils; preparation of cords, treads, and beads; and assembling them into tires. The tires are then vulcanized under pressure by means of steam heat. This processing requires heavy machinery as well as conveyors and other equipment for handling the many materials involved. Nearly all of work must be done under carefully controlled conditions of temperature and humidity, which meant that bomb-damaged buildings must be repaired before operation could be resumed. The machinery, such as mixers, mills, and calenders, was usually not crippled unless hit by a 1,000-lb bomb or heavier. The rubber plants very susceptible to fire because of the highly inflammable materials used and the large floor areas required.

Attacks. Apparently the rubber fabrication industry was never a first-priority target for air raids, but these plants were located in large cities and were badly damaged by area raids and spillovers from attacks on other targets. Normal production levels were maintained through 1943 and early 1944. Damage caused by raids was repaired rapidly, and when vital equipment was damaged the production was allocated to other plants. Production charts of Continental (...) indicate how production was affected (Figures 114). Of these, only Continental suffered appreciable damage before October, 1944.

The Continental Rubber Company operated four plants in Hannover, but only the main plant was appreciably damaged by air attack. It consisted of 52 buildings, 60 percent of which were of steel frame construction with concrete fireproofing and 25 percent were reinforced concrete. The other 15 percent, which were not classed as fire resistant, were of brick or nonfireproofed steel frame construction. Half of these buildings were totally destroyed or severely damaged, and all were damaged to some extent. Even though the buildings were badly damaged, the heavy machinery of the plant survived and could be reinstalled in one of the other plants in Hannover without much lost time.

Of the 105 attacks made on the city of Hannover and the adjacent areas, 14 resulted in hits on the Continental plant, which received a total of 73 tons of bombs. Hits totaling 2 1/2 tons on 9 and 18 October 1943 resulted in a temporary loss of 30 percent in production, and the attack of 9 March 1944 caused a loss of 13 percent. From October, 1944, curtailed electric power supply caused by the area raids reduced the Buna rubber consumption to less than 1,500 tons per month. Periodic hits after that time caused temporary interruptions in production until 25 March 1945, when 49 tons of bombs struck the plant and closed it down (see Figure 114). In spite of the serious damage done to the buildings, the plant could have beep brought back to 30 percent of normal capacity in about four months.

Conclusions. The results of bombing of these plants indicate that they can be knocked out most completely by destroying the mixing room, if its location is known. In most plants mixing is centralized and is vital to operation of the plant. However, it should be noted that destroying the mixing room would require many hits with large bombs (1,000 lb or heavier) and fuze settings for maximum fragmentation damage. Of equal importance is damage to the steam boilers because rubber fabrication plants are helpless without high-pressure steam for vulcanization. Destruction of the fabric preparation departments and the loss of prepared fabric would stop the production of tires. This would require a heavy concentration of incendiaries after destruction of the roof by high explosives. In general, destruction of roofs and buildings is quite effective in slowing down production, because these plants cannot operate without weather protection.