The How and Why Air Attacks Crippled the German Oil-Chemical
Industry:
Synthetic Ammonia and Methanol Targets
Ammonia and methanol were starting materials for a large part of -the German
chemicals production, both organic and inorganic. These products were made by
two basic syntheses from gases: hydrogen and nitrogen for ammonia, hydrogen and
carbon monoxide for methanol. The syntheses were very similar, being carried out
at high pressures (3,500 lb per square inch), at high temperatures, and in
almost identical equipment. The gases for both processes were made from coal,
air, and water in common equipment. Because all three basic processes use the
same raw materials and same types of equipment, they were frequently all found
in the same plant. Consequently, although methanol and ammonia plants were not
priority targets for air attack, these plants were attacked in conjunction with
synthetic oil units with which they were integrated. The production of
explosives, fertililizers, and other chemicals was thus fortuitously curtailed,
and an opportunity was afforded for studying the effects of bombing on such
targets.
Survey of Ammonia and Methanol Plants. Of the plants listed in Tables
1 and 19 Oil Division survey teams made detailed examination of three,
Gewerkschaft Victor at Castrop-Rauxel and I.G. Farbenindustrie A.G. plants at
Leuna and Ludwigshafen-Oppau, representing two thirds of Germany's synthetic
nitrogen and half her methanol capacity. Another nitrogen plant, Ruhrchemie at
Holten, was visited.
Synthetic Ammonia and Synthetic Methanol. There is little resemblance
between ammonia and methanol physically and chemically; yet the methods of
producing them synthetically are so similiar that they may as well be considered
together in studying the effects of bombing the plants. Both are made by the
basic synthesis of gases from the same raw materials: coal or coke, air, and
steam. Both depend on the consumption of large amounts of similar
utilities-steam, power, (electricity, steam, or gas), and water.
Ammonia is made by passing a mixture of relatively pure nitrogen and hydrogen
over a bed of catalyst at high pressure (3,000 to 3,500 square inch) and
temperature (750° F) in heavy-walled equipment. Methanol and the higher alcohols
are made the same way except that the gases employed are hydrogen and carbon
monoxide, and different catalysts and slightly different operating conditions
are employed.
To produce hydrogen, nitrogen, or carbon monoxide, the same raw materials,
coal or coke, air (or oxygen), and steam are used; the same equipment units,
water-gas generators and gas producers, are employed. The composition of the
finished gas is dependent on the distribution of the steam, air, and oxygen
used; the distribution between water-gas generators and gas producers (often
interchangeable); and the method of final purification. The gases must be
purified to remove sulfur (recovered in the plants studied to make sulfuric acid
and pure sulfur), carbon dioxide, and carbon monoxide (for the ammonia
synthesis), and must be treated catalytically to adjust the carbon monoxide
content. The gas producing and purification equipment is bulky and intricate. It
is of light construction, operating at low -pressure, and covers a large area.
Thus the gas producing and purification facilities offer an excellent bombing
target owing to their size and structural weakness, and finally because their
elimination would cause a break in the chain of integrated production.
On the other hand, these plants are made up of many parallel units. At Leuna,
for example, there were 65 gas generators, most of them capable of serving as
either water-gas generators or gas producers (for gas with nitrogen). In the
same plant were 40 activated carbon-type desulfurizing units supplied by 18 gas
blowers. The plant had 139 gas converters for the shift reaction. To knock the
gas plant out completely, most of these would have to be damaged, a fairly
difficult task. All this equipment, however, was collected into an area of 30
acres where it presented an excellent target of vital and vulnerable units with
no spare capacity outside the area. In the plants studied, the gas generating
and purification equipment had not been extensively hit by bombs, although it
should have been a primary aiming point more often.
Right - Figure 111. General view of Leuna Works looking south, reproduced
from German pictures taken some years before the war. The 13 tall chimneys on
the boiler houses helped fliers identify the plant.
The synthesis units proper consisted of heavy-walled vessels (reactors,
coolers, separators) of alloy steel, transfer lines, and heaters of heavy-walled
pipe, and the high-pressure compressors, and pumps. All this equipment is vital,
in that, if it is damaged beyong repair, months are required for replacement. On
the other hand, most of it was well protected by concrete and brick walls.
Unless such equipment received direct hits from bombs or near misses from very
large bombs, it was not damaged. Flying fragments of bombs had little effect on
it. Examples were found of 500-lb bombs exploding within a yard or so of
high-pressure compressors protected by concrete walls without damaging the
compressors. Direct hits or near misses by large bombs on compressors
effectively put them out of commission, but since a large plant consists of
numerous compressors in parallel, all must be damaged if the plant is to be shut
down. The synthesis plants, therefore, were not choice targets, especially when
bombs were small and the aiming conditions unfavorable.
The enormous utility requirements of a high-pressure synthesis - steam for
gas production, power for gas compression, and water for cooling (with
corresponding sewer capacities) - suggest the choice of power plants or utility
transfer equipment as a target. They were not feasible targets, however, since
they covered such a large area. Not many hits were observed on boilers or
generators, but there were some effective ones on boilers or generators.
Likewise, water treating or pumping plants are vulnerable. The Germans expressed
suprise at our not bombing the coal unloading and transfer equipment at Oppau,
which would have in their opinion have been very effective. Utility transfer
lines including sewers were damaged frequently by the numerous bombs, large and
small, falling in the plants studied.
How Production Was Stopped. In the methanol and ammonia plants
studied, production was stopped largely by the destruction of man-hours rather
than equipment. The physical damage caused by the bombing was largely of a
reparable nature. The return of the plant to production was therefore usually a
question of how quickly repair could be made.
While there were numerous isolated cases of permanent damage to equipment
such as compressors, pumps, and electric transformers, this damage (usually
occurring on pieces of equipment present in multiple units) did not in most
cases curtail production because of the excess capacity of the individual
sections of the German plants. The greatest single factor in shutting down the
plants producing methanol and ammonia was the destruction of utility transfer
equipment, especially electric cables, water lines, sewers, and steam lines.
While the materials requirements were not excessive, the strain on man power in
making repairs was heavy, and the production loss accumulated.
The loss of production at both Ludwigshafen and Leuna was the result of
repeated bombings, most of which temporarily stopped production of the plant by
reparable damage, usually to utility lines. As soon as the plant could be
repaired and production resumed, another attack would be carried out and the
cycle repeated. At Leuna the production of the plant averaged only about 9
percent of capacity (7 percent for methanol and ammonia because of priorities)
after the air attacks recommenced in May, 1944. At Oppau the plant production
for the four-month bombing period ending December 15 was about 30 percent. From
then on it was essentially nothing.
Left - Figure 112. Verticalaerial view of Leuna Works, taken by the Luftwaffe in August, 1944.
War History of a Typical Nitrogen and Methanol Plant
Ammoniakwerk Merseburg (Leuna), a typical plant producing ammonia and
methanol (integrated with other chemicals and liquid fuels production), is
located at Leuna near the Saale River. It is over 11,000 ft long, up to 3,500 ft
wide and occupies 757 acres, of which area 23 percent is occupied by buildings
and tanks. The plant produces liquid fuels, ammonia, methanol, and the higher
alcohols, by three basic high pressure syntheses from gases derived from coal,
coke, air, oxygen, and steam. Chemical derivatives from the basic materials
comprise some 80 products including synthetic fuels and lubricants, fertilizers,
acids, various solvents, organic chemicals, plastics, etc. In 1943 the monthly
production of the plant was 21,000 tons of nitrogen, over 14,900 tons of
methanol, and 600 tons of isobutyl alcohol. This was approximately 32 percent of
the synthetic nitrogen and 72 percent of the methanol production of Germany.
Some idea of the size of the plant, may be gained from the following figures. It
aconsumed annually over 1,000,000 tons of by-product coke, 400,000 tons of brown
coal tons of brown coal; gas production in the plant for process and fuel
exceeded 390,000,000 cu. ft. daily; water was consumed a rate of up to 180,000
gpm; the steam generating capacity was 4,300,000 lb per hour and the connected
electric load 390,000 kw (see Figures 111, 112).
Air Attacks. The Leuna plant was attacked from the air 22 times
starting on 12 May 1944. The striking feature of these attacks ewas that, every
time more than a ton of bombs hit the plant, production came to a halt, but not
permanently. After each attack the Germans industriously repaired the damage and
attempted to get the plant in operation. Production seldom approached an
appreciable proportion of capacity before a new attack again terminated the
activity. This is illustrated graphically in Figure
113, which shows the production of nitrogen, methanol, and the closely
related (from a process viewpoint) isobutyl alcohol for the year 1944.
The chief factor causing loss of production was the destruction of utility
lines, including sewers, without which the plant could not be operated. Although
widely distributed, this damage could be repaired by available labor and
materials. After sustaining 22 major attacks, the plant was still in such a
basically sound condition that it could have been returned to 70 percent of
normal production capacity in a few months without requiring the replacement of
essential equipment.
Personnel. The plant employed during and just previous to the war
about 33,000 persons, including 10,000 foreigners and 2,300 German women. There
were 4,100 office workers (815 German women) and 400 chemists and engineers.
During the strategic bombing period 301 workers (1 percent) were killed and 795
(2.4 percent) were injured. These figures are typical of the industry. The
morale was generally good except after the first two attacks when inadequate air
raid shelters led to panic and absenteeism.
Defense Measures. Over 19,000 (about 60 percent) of the plant's
employees were organized in a very effective air raid protection organization.
About 30,000,000 RM were spent up to 1942 for equipment for personnel, decoy
plants, protection against bomb fragments, air raid shelters, etc. Smoke screens
were generally used, and they were effective. On several of the first eight
attacks (the only ones where data are available) more bombs fell on the decoy
plants than on the Leuna Works. The active defense by anti-aircraft batteries
was very effective, especially during the late summer and early fall of 1944
when 500 to 600 guns were in use. Of these one fourth were 128-mm guns, the rest
105-mm and 88-mm.
Impressions and Recommendations. It is probable that the production
would have been stopped for longer periods had the physical damage exceeded the
capacity of the plant personnel to repair it swiftly. This obviously could have
been realized by either of two methods: (a) Dropping more bombs on the plant by
increasing the size or number of the attacks.
(b) Hitting the plant more
frequently by more accurate aiming.
Only 10.1 percent of the bombs dropped
fell within the plant area, leaving a considerable opportunity for improvement
in this respect.
Production could have been stopped for longer periods had the nature of the
damage been such that repair materials from outside sources were required, or
had vital equipment, such as heavy compressors, pumps, and electric generators,
been destroyed. For a more effective stoppage of production in an ammonia and
methanol plant like Leuna, permanent dislocation of some vital part of the plant
should be effected. This requires the use of large bombs on some vital part of
the plant, such as gas production and purification units.
Above - Figure 117. View of Leuna Works, taken by the Eighth Air Force in
May, 1945. Foreground, the organic products division. Right middle distance, the
hydrogenation area. The group of 11 chimneys in the distance marks the older
boiler and power plants. To the left of them is the gas production area.
Table 39 is an attack and damage log showing bombs dropped, bombs hitting the
plant, production status before and after raids, damage inflicted, and
recuperability.
Table 39
Damage from Air Attack on Synthetic Ammonia and Methanol Plant at
Leuna
| Daily Production, Percent of Normal | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Date of Attack | Bombs Dropped, Tons | Bombs Exploded in Target Area, Tons | Before Attack | 2nd Day | 7th Day | 14th Day | Cause of Production Loss and Other Major Damage | Estimated Recuperability, Percent of Capacity of Plant After Attack | Damage, Reichmarks |
| 12 May 1944 | 490 | 95 | 96 | 0 | 0 | 8 | Damage to ultilities: Steam lines, over 100 major breaks; water lines, over 50 major breaks, power cables, 100 major breaks. Telephone system and siren were out. 15 large fires started. Building damage: 7,000,000 cu. ft. severely damaged; 19,000,000 cu. ft. moderately and 67,000,000 cu. ft. lightly damaged | Operations started in 10 days | 45,800,000 |
| 28 May 1944 | 133 | 41 | 8 | 0 | 0 | 22 | Complete loss of all utilities due to 150 major breaks in utility piping and 110 major cable breaks. Telephone office severely damaged. Building damage: 800,000 cu. ft. of building volume totally destroyed; 12,000,000 cu. ft. severely damaged; 5,000,000 cu. ft. moderately and 16,000,000 cu. ft. lightly damaged | 20 in 15 days 50 in 15 days 70 in 22 days 100 in 84 days | 9,900,000 |
| 7 July 1944 | 93 | 31 | 76 | 0 | 31 | 0 | General damage, but no important single items. 194 major breaks in utility lines | 40 in 7 days 80 in 14 days | 5,900,000 |
| 20 July 1944 | 361 | 87 | 53 | 0 | 35 | 0 | The southern part of the plant was severely hit. 264 new breaks were found in the pipeline system. Gas generation, ammonia synthesis, and the Salts Division suffered damage. Damage to sewers and railroads created bottlenecks in production for a few days | 50 in 11 days 70 in 14 days 85 in 27 days | 14,120,000 |
| 28/29 July 1944 | 1,584 1,361 2,945 | 214 77 291 | 35 | 0 | 0 | 0 | Complete loss of all utilities due to 410 major breaks in water lines; 400 to 500 in steam lines. Damage to cables and substations was very great. Coal conveyors to boiler houses Me 3, Me 4, Me 202, Me 203 would be out of operation for 6 to 14 weeks. Three boilers destroyed and 9 damaged. 17 turbogenerators damaged. Repairs to gas lines would determine when operations could be resumed. Gas generators damaged. Damage occured to compressors, scrubbers, cooling towers, and recycle gas compressors. Hydrogenation, methanol, and aklylate distillation were damaged. Dehydrogenation ovens in the alkylate plant were put out of service. Mechanical shops were badly damaged | 20 in 17 days 40 in 60 days 50 in 90 days 65 in 120 days 80 in 150 days | 66,320,000 |
| 24 Aug. 1944 | 450 | 75 | 0 | 0 | 0 | 0 | Waterworks at Daspig hit, and the boiler house put of commission. 273 major breaks were located in the utility lines. Gas production and purification areas were severely hit. Alkyation plant would be out of production for weeks | 25 in 30 days 33 in 60 days 42 in 90 days 52 in 120 days 70 in 180 days | 16,900,000 |
| 11 Sep. 1944 | 240 | 16 | 0 | 0 | 0 | 0 | Gas recovery units in Hydrogenation Division were damaged. Smoke acid production will be out for weeks because of hits. The Linde plant and the Haeuber installations in the ethylene plant were damaged. Gasholders destroyed | No delay in previous plan | 13,100,000 |
| 13 Sep. 1944 | 330 | 83 | 0 | 0 | 0 | 0 | Waterworks at Dasig received 70 hits. Water intakes, filters, boiler house, and main pump house seriously damaged. Repairs to the inlet line estimated to take weeks. Sewers also received hits. Three 1,700-lb boilers received direct hits. Gas production and purification department was hit again. Several compressors used in ammonia synthesis received direct hits. This would be the bottleneck in the starting up of the hydrogenation plant. Water pumps in methanol plant damaged. Formaldehyde, propionaldehyde, and alkylate plants received hits. The whole plant must be prepared for winter operation, which will slow down repairs. The number of major pipe breaks from this and the preceeding attack was 304 | Four weeks' delay in previous plan | Included in above figure |
| 28 Sep. 1944 | 725 | 33 | 0 | 0 | 0 | 0 | Coal conveyor for boiler house Me 203 was severely damaged; it would take months to make repairs. The switchgear in powerplant Me 5 was again destroyed. Gas generator and the coal conveyor to gas generator building to Me 240 were severely damaged. The last large gas holder was destroyed. High-pressure water scrubbing unit was damaged severely. Mechanical shops were seriously hit | One week's delay in earlier plan | 3,270,000 |
| 7 Oct. 1944 | 278 | 1 | 0 | 0 | 0 | 12 | Water lines to Daspig were hit again. One week to effect repairs. No damage in plant proper | 10 in 10 days 20 in 20 days 35 in 60 days 58 in 90 days | 53,000 |
| 2 Nov. 1944 | 1,324 | 1 | 20 | 10 | New attacks | Outside electric power failed owing to direct hits. No damage in plant proper | No delay in previous plans | 116,000 | |
| 8 Nov. 1944 | 498 | 0 | 20 | 22 | 24 | New attacks | Parctically no damage in plant | No delay in previous plans | 21,000 |
| 21 Nov. 1944 | 503 | 54 | 28 | 0 | 0 | 8 | Report of this attack missing | No data available owing to following attacks | 8,370,000 |
| 25 Nov. 1944 | 1,747 | 55 | 0 | 0 | 1 | New attack | Coal conveyor for boiler house Me 204 hit again. One boiler in Me 202 destroyed. Electric power to Daspig failed | No data available owing to following attacks | 5,130,000 |
| 30 Nov. 1944 | 595 | 39 | 0 | 0 | 1 | New attack | Hits on railroad put it out of commission for several days. The electric switch installation in compressor building Me 187 was severely damaged. Distillation units in the Hydrogenation Division received direct hits. The south end of the plant was hit by 200 bombs. Cables, sewers, and water lines were very seriously damaged. Cooling tower Me 984, the alkylation plant, catalyst manufacturing plant, and the Mersol and Mesomoll plants were severely hit | No data | 6,245,000 |
| 6 Dec. 1944 | 1,044 | 46 | 8 | 0 | 0 | 0 | Railroad yard received 20 to 30 hits. West camp completely destroyed, leaving 1,700 persons without shelter. Four boilers destroyed. Coal conveyors in Me 108 hit causing two-week shutdown in boiler house Me 203. One turbogenerator in Me 203 was damaged severely. One third of feed water treating plant was lost. All utility pipeslines and cables very heavily damaged. Gas lines in producing and purification plants were hit by 60 bombs. Methanol plant was hit and a large crane damaged | No data | 25,620,000 |
| 6/7 Dec. 1944 | 1,828 | 72 | 0 | 0 | 0 | 0 | A large flue was destroyed; four boilers, two bunkers and three feed water pumps damaged. Two hits in coal conveyor Me 224. One turbogenerator was severely damaged. One half of a substation in south plant was destroyed. Phenol water plant damaged. Compressors and high-pressure buildings in ammonia plant severely damaged. Adipic acid and nitric acid plants were hit again. The electric power distribution in the hydrogenation distillation suffered great damage. Seven stalls used in alcohol synthesis were severely damaged, causing a reduction in production of 70 percent. Mechanical shops were severely damaged | No data | Included in previous attack |
| 12 Dec. 1944 | 985 | 18 | 0 | 0 | 0 | 0 | Coal conveyor in Me 990 received four hits causing a two- to three-weeks shutdown. Tank fire broke out in Hydrogenation Division (Me 825). Building damage in DHD installation. Lubricating oil, Haeuber, and activated carbon plants were damaged. Main sewer received one hit | 10 in 18 days 19 in 30 days 35 in 60 days | 1,980,000 |
| 14 Jan. 1945 | 2,413 | 260 | 15 | 0 | 0 | 0 | Gas production and purification installations were hit heavily. Last operable shift reaction building heavily damaged. Damage was also sustained to extraction unit of sulfur removal, north end of water-gas plant, blower house, and coke conveyors. Recirculating compressors, paste pumps, oven stalls, and control rooms, large crane, distillation unit, DHD unit, and centrifuge building. The Organic Division was hit in the following places: Methanol and isobutyl oil distillation and tank storage, alkylate plant, Mersol plant and a great number of all pipe bridges. All shops were hit hard. Outside power supply cut off. Some boilers received direct hits. Feed water treating plant Me 288 was damaged which reduced the available steam supply. A chimney in boiler house Me 4 collapsed. Railroads and coal transportation was badly interrupted; central kitchen was destroyed. Telephone system was badly crippled. Office buildings were barely usable. 712 major breaks in utility lines. | Start up in 30 days 18 in 60 days 25 in 90 days 30 in 120 days 35 in 150 days 70 in 270 days | 57,800,000 |
| 4/5 April 1945 | 1,113 | 61 | 20 | 0 | 0 | 0 | A large fire started in the Hydrogenation Division, another in the camp at Dasig. Water supply was cut for ten days by hits in water lines. Sewers were also hit. Shift reaction building severely damaged by blast. One hydrogenation stall was hit, and the gas circulation system and the low-pressure department of this Division were damaged | 60 to 70 in 10 months | No data available |
Synthetic Rubber Targets
The equipment used in synthetic rubber plants is similar in most respects to
that employed in refineries and hydrogenation plants. There are, of course,
numerous items which are required for processing steps specific to rubber
synthesis. The plant at Huels, with an actual capacity of 40,000 tons per year,
occupies an area of 541 acres (about 10 percent built up), and cost
approximately 400,000,000 RM, of which the greater part was invested in crude
rubber manufacturing equipment. This compares with the 100,000,000 RM cost of a
hydrogenation plant occupying 188 acres and producing 150,000 tons per year.
Process. Synthetic rubber, a complex hydrocarbon, was prepared from
coal in an intricate series of chemical processes. Butadiene, used in the
preparation of synthetic rubber of the Buna type which is now being manufactured
in the United States from petroleum or grain, was manufactured in Germany
primarily from acetylene. This gas, it will be recalled, was used in early
automobile and bicycle lamps and, in recent years, has become better known as a
welding gas. The Germans had devised several methods for preparing
acetylene.
Schkopou, Leverkusen, and Ludwigshafen used the most familiar one in which
water is sprayed an lumps of "carbide." A move recent development, which
involves subjecting the hydrocarbon gases to the high temperature of an electric
arc, causing the gases to decompose to acetylene, was used at Huels. The
acetylene is purified, converted in the presence of a mercury catalyst to a new
material, acetaldehyde, which is then transformed chemically to aldol and
subsequently to butylene glycol by hydrogenation at 3,000 lb per square inch.
The butylene glycol is then dehydrated to butediene, one of the two principal
raw materials for Buns. Part of the acetylene is hydrogenated at low pressure to
ethylene, which is treated with benzol to make ethyl benzene and subsequently
dehydrogenated to styrene, the other principal constituent of Buna rubber. These
two substances are allowed to combine to form latex in a series of mixing
vessels, and then coagulated, washed on a wire screen, dried, and pressed into
sheets.
Vulnerability. Synthetic rubber plants are vulnerable to air attacks
much in the same respects as refineries and synthetic oil plants. The various
items of cri tical equipment include low-temperature gas fractionation plants,
compressors for hydrogen, adsorption towers, fractionation towers, pumps,
autoclaves, cranes for transporting heavy vessels, and various special types of
equipment peculiar to the chemical industry. Gasholders are highly important, as
in the case of Fischer-Tropsch plants. Cooling towers are also numerous because
tremendous quantities of water are required. At Huels, the power plant supplying
the electric arcs was an important target, particularly since no excess
power-generating facilities existed. From the standpoint of inflicting reparable
damage, the mazes of pipe bridges and electric cables provided vulnerable
objectives. Breaks in the pipe lines supplying gas from outside the plant
confines rendered the plant temporarily inoperable.
These plants should be markedly vulnerable to incendiaries properly employed,
since hydrogen, butodiene, ethylene, natural gas, acetylene, etc., all highly
inflammable, are piped throughout the entire plant, Moreover, numerous
inflammable liquids, such as alcohols, aldehydes, styrene, ethyl benzene, and
the like, circulate through the various stills. Rubber fires are also extremely
difficult to control, as was evidenced at the Huels rubber storage warehouse. An
essential condition, however, is an adequate use of high-explosive bombs to
release inflammable materials.
Air Attacks. The synthetic rubber industry rarely given top priority
by the target selection groups. During the strategic bombing offensive, starting
12 May 1944, 480 tons of bombs directed at Huels, 826 tons at Leverkusen, 13,670
tons at Ludwigshafen. The high tonnage dropped at Ludwigshafen was directed at
oil production. The relatively smaller tonnage directed at Huels and the absence
of attacks on Schkopau - far more important rubber producers - indicate the low
priority of rubber targets. Late in 1944, Huels suffered a production loss owing
to the combined effects of lack of gas and destruction of rail facilities - the
latter factor eliminating operation with externally purchased intermediates.
Schkopau was rendered inactive by air attacks on Leuna which prevented
deliveries of hydrogen. Leverkusen, a small rubber producer, was bombed out by
attacks on its chemical plants.
War History of a Typical Synthetic Rubber Plant
The Chemische Werke Huels represents the latest and most modern design of
German synthetic rubber plants. Controlled and operated under the direction of
the I.G. Farbenindustrie, the plant, located in the Ruhr, north of Essen, had a
rated capacity of 4,000 metric tons per month, making it the second largest Buna
plant in Germany. It was built under the auspices of the German four-year plan
and began production in August, 1940.
Production. Huels was the only plant in Germany which manufactured
acetylene by the electric-arc cracking of hydrocarbon gases. For sytrene
production, benzene was obtained from coal-tar plants in the Ruhr, and ethylene
was produced at Huels. Related organic rubber softeners, including sulfur, were
also manufactured. The capacity of the plant increased gradually from 300 tons
during the first month to 4,000 tons by January, 1943. Except for slight
interruptions, this production was maintained until 22 June, when the plant was
shut down by bombing attack. There was a sharp decline during the last half of
1944 and the first quarter of 1945 as a result of damage to Scholven and
Gelsenberg, the two plants supplying the major part of the raw hydrocarbon
gases. As an alternative source, a pipe line was laid from the Bentheim natural
gas wells in Holland, but this source was able to supply only 35 percent of the
Huels normal requirements.
Air Attacks. The most effective bombing of the plant occurred on 22
June 1943, when 182 airplanes of the Eighth Air Force, in its first daylight
mission over Germany, dropped 448 tons of bombs, of which 321 bombs weighing
88.6 tons exploded inside the plant area. A direct hit caused the main acetylene
gasholder to explode with considerable resultant damage. There was also heavy
loss of life (186 persons killed). Workers standing in the open were admiring
what they thought was an admirable Luftwaffe spectacle when the bombs came down.
The plant was shut down for one month for repairs, and full production was not
achieved again for six months. Aside from a few sporadic bombs and ineffective
attacks just prior to occupation of the area by the Allied forces, Huels was
unmolested for the rest of the war and operated until 29 March 1945, the day the
plant was occupied by elements of the U. S. Ninth Army. The plant, at this time,
was practically intact and, except for lack of gas, could have started rubber
production at essentially full capacity. During the entire period of the war,
1,367 tons of bombs were directed at this plant, of which approximately 12.5
percent hit the target. In a single raid on 17 March 1945, 480 tons of bombs
were reported aimed at the plant but none of them hit it.
Damage. The plant was built up, for the most part, of a series of
parallel operating units so that permanent stoppage of production necessitated
destruction of all of one or more types of equipment through which the critical
process streams had to pass. The following list is indicative of the precautions
taken by the Huels management to insure partial production even though parts of
the plant were rendered inoperable by air attack.
| Major Processing Equipment | Number Installed |
|---|---|
| Turbogenerators | 15 |
| Acetylene arcs and rectifiers | 15 (3 more under construction) |
| Carbon black recovery systems | 15 |
| Arc gas scrubbing plants | 6 |
| Acetylene purification systems | 4 |
| Acetaldehyde synthesis units | 7 |
| Aldolization units | 6 |
| Butylene glycol distillation systems | 2 |
| Butylene glycol dehydration reactors | 18 |
| Butadiene distillation systems | 3 |
| Linde hydrogen plants | 7 |
| Linde air separation units | 4 |
| Acetylene hydrogenation systems | 6 |
| Linde ethylene concentration units | 4 |
| Benzol refining systems | 3 |
| Ethyl benzene alkylation units | 8 |
| Ethyl benzene dehydrogenation units | 17 |
| Styrene distillation systems | 5 |
| Buna polymerization, coagulation, and finishing | 8-9 |
In addition to the main rubber raw materials and rubber producing equipment
listed, the equipment used for making miscellaneous chemicals was also installed
on the parallel system principle.
In the important raids, the damage which temporarily eliminated production
was mainly of the reparable type. Pipelines, cables, water mains, and gas
distribution systems were damaged. There was relatively little damage to process
equipment. Such items as were affected and the munitions responsible
were:
Crude ethylene compressor damaged by two 1,000-lb bombs.
Air
separation units destroyed by one 1,000-lb bomb. 2 transformers destroyed by two
1,000-lb bombs.
1 turbine in turbogenerator set destroyed by three 1,000-lb
bombs.
Gas compressor destroyed and 5 others (also switchgear) damaged by one
1,000-lb bomb.
Conveyor belt system in carbon black plant destroyed by one
1,000-lb bomb.
3 centrifuges and motors in aldol plant destroyed and 8
centrifuges damaged by one 1,000-lb bomb.
In the butylene glycol
distillation, 20 pumps and 9 small vessels destroyed, and 3 vessels and 8 pumps
damaged by two 500-lb bombs.
Numerous gasholders destroyed.
The fact that
vital equipment suffered only minor damage was undoubtedly largely responsible
for the rapid recovery to maximum production level.
Defense Measures. The Huels plant was defended by a fairly heavy flak
concentration and also had the advantage of the Ruhr area defenses, which
included searchlight belts, heavy flak, and fighter interception bases. The
plant was equipped with installations for smoke screening, but, because of the
short distance involved, it was found impossible to blanket the area before the
bombers reported crossing the Channel were over the target. The most elaborate
camouflage system encountered anywhere in Germany was employed at this plant. It
consisted of wire netting and glass wool, with small structures erected on the
netting to resemble tree and shrubbery. The cost of installation was 4,000,000
RM. Aerial photographs indicated its ineffectiveness. Reinforced concrete bunker
type shelters were provided following the heavy casualties in the 22 June
attack.
One complete acetaldehyde plant and one ethyl benzene plant were dispersed to
an underground location in Mettenheim, Bavaria, but had not begun production
when the war.
Personnel. For full operation, the plant required a total personnel of
10,400 employees, of which 2,400 were women. Two thousand additional persons
were employed for maintenance and construction work. Morale was not put under a
heavy strain and, consequently, remained high. Absenteeism averaged
approximately 5 percent.
Conclusions. The brief attack history of this synthetic rubber plant,
one of the most vital units in the entire Nazi war economy, indicates that
plants of this type can be shut down for short periods by damage to utilities
and for long periods by destruction of vital equipment. Any part of the plant is
vulnerable to bombs. In this particular plant, the most vulnerable section was
probably the water supply which was pumped from the Lippe River by a single
pumping station. Destruction of the water pumping facilities would have kept the
plant out of operation, by German estimate, for at least three months. The
destruction of any step in the interlocking system of processes would have put
the entire plant out of action. Production can be stopped more effectively for a
long period of time by the total destruction of a single vital plant than by
strewing bombs over the entire works and number of plants.
Table 40 is an attack and damage log, including dates of attacks, bombs
dropped, bombs hitting the target, description of damage, and estimate of
recovery capacity.
Table 40
Damage from Attacks on the Synthetic Rubber Plant, Chemische Werke Huels
(1940-1945)
| Date of Attack | Bombs Dropped, Tons | Bombs Exploded in Target Area, Tons | Average Weight of HE Bombs, Pounds | Cause of Production Loss and Other Major Damage | Recuperability After Attack, Estimated by Plant | Damage in Reichmarks, Reported by Plant |
|---|---|---|---|---|---|---|
| 17/18 June 1940* | Not known | Not determined | Production had not started | 161,000 | ||
| 12/13 June 1941 | 6 | 0 | 670 | None reported | None | |
| 6/7 Sep. 1941 | 49 | 2.90 | 580 | Water main broken; secondary damage by flooding. 1 man badly wounded | Few days | 1,193,000 |
| 12/13 Sep. 1941 | 36 | 0 | 1,106 | None reported | None | |
| 28/29 Dec. 1941 | 67 | 29.28 | 1,046 | Pipe bridge destroyed; Buna finishing fired. Gasholder blew up. Explosion destroyed 4 other gasholders. High-pressure gas line hit, gas caught fire. Fire acted as flare for attacking airplanes. Buildings damaged, water connections broken, acetylene scrubber damaged, motor insulation pierced. 7 dead; 31 slightly wounded | 14 days to repair Buna finishing; gasholder damage would take months; complete repairs of line breaks would require at least 4 weeks. Damage to acetylene scrubbers, 4 weeks. Estimated capacity in 4 weeks, 50 percent Actually operated at 30 percent for first month, 80 percent for second month, Kybol production out for first quarter of 1942 | 6,846,000 |
| 13 June 1943 | 3** | 3** | 3,000 | One HE exploded below roof of power house hitting 9 turbines. 1 generator and turbine completely destroyed. Aldol evaporators damaged. Could not make up by aldehyde purchases | Loss of 10 percent production for June. Power taken up from grid to make up part of loss | 71,000 |
| 22 June 1943 | 448 | 88.59 | 552 | "Practically all manufacturing buildings in difficulty." Total casualties 186 dead; 500 slightly wounded | Estimate 1/4 capacity by beginning of August. Full production possibly by beginning of 1944 Actually realized 36 percent of capacity in 40 days, 72 percent in 3 1/2 | 32,345,000 |
| 22/23 May 1944 | 12* | 1* | 1,000 | Contact plant of butadiene reactor building and gasholder hit. Fragmentation damage in pipelines. 4 dead; 22 slightly wounded | 5 days production loss | 1,200,000 |
| 8 March 1945# | 260 | 39.37 | 508 | Damaged mostly offices, garages, and repair shops. Buna store fired by HE. 500 tons of Buna burned 3 killed; 14 wounded | Estimate 2,000 tons per month production loss Butadiene would be short | None reported |
| 14 March 1945 | 6* | 5.25* | 500 | Benzol column hit. Styrene columns hit. Cooling tower for power house damaged. Graphite electrode shop destroyed. Explosion of acetylene line and holder. Water line hit. Turbine with generator damaged. 3 dead; 29 wounded | 2-3 weeks loss | None reported |
| 17 March 1945 | 480 | 0 | 746 | None reported | ||
| Total | 1,367 | 169.39 | ||||
| * Attack not indicated but hit the plant | ||||||
| ** Crippled airplane from raid of Bochum jettisoned bombs on plant. | ||||||
| # Not in official Air Air Force records. | ||||||
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, the two largest were Continental Rubber at Hannover and Dunlop at Hanau.
In 1943, Continental accounted for 45 to 55 percent of the tire production of
Germany and Dunlop for 14 percent; Phoenix at Harburg, the fifth largest plant,
made 5 percent of Germany's tires. In addition, these plants produced large
quantities of footwear and other rubber goods.
Table 41
Consumption Of Crude And Synthetic Rubber In German Fabricating
Plants
| Plant | Consumption of Crude and Synthetic Rubber, 1943, Tons | Approximate Percent of Total Consumption | Products |
|---|---|---|---|
| Continental-Hannover | 36,000 | 40 | Tires, tubes, mechanicals |
| Dunlop-Hanau | 11,000 | 12 | Tires, tubes |
| Phoenix-Harburg | 5,500 | 6 | Tires, tubes, mechanicals |
| All others | 38,500 | 42 | |
| Total Germany | 91,000 |
Vulnerability. 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, Dunlop, and Phoenix indicate how production was affected (Figures 114, 115, and 116). Of these, only Continental suffered
appreciable damage before October, 1944.
Damage. On 12 December 1944 the Dunlop factory was shut down when 30
tons of bombs aimed at the marshaling yards about one third of a mile away hit
the plant. It would have recovered about 20 percent of its capacity by the
middle of February, 1945, but attacks on the marshaling yards and the town of
Hanau on 6 and 7 January 1944 eliminated it for the rest of the war because
materials were not available for repair.
The Phoenix plant at Harbu rg was hit by 7 tons of bombs aimed at the near-by
Rhenania Oil Refinery on 25 October 1944 and 3 tons more on 21 November 1944.
These two attacks resulted in an 80 percent loss of production which had not
been recovered when the plant was shut down completely by attacks on 7 and 31
March 1945. The bombs which hit Phoenix found key points such as the mixing,
spreading, and tire departments, and shut the plant down without demolishing it.
It could have been brought back to 60 percent of normal production in two months
had the necessary skilled labor been available.
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.
Other important plants, such as Metzler at Munich and Gummiwerke at Fulda,
were also put out of action late in 1944.
This series of blows cut tire production to less than one third, as indicated
by natural and synthetic rubber consumptions: 3,078 tons in September, 1944;
1,065 tons in January, 1945; and 953 tons in February, 1945 (Figure 55). Estimates of the residual capacity
of the nine largest fabricators is given in Appendix Table C10.
Production of mechanical goods was also substantially reduced by bombing.
Paguag at Dusseldorf was hit on 23 September 1944 and eliminated by the attacks
of 2 and 3 November 1944. Clouth at Cologne was knocked out 3 October 1944, and
the Gummi Faden Fabrik at Cologne was hit on 15 and 28 October. These plants
turned out such items as belting, rolls, rubber threads, gas masks, and
packing.
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.
Below - Figure 118. The Ludwigshafen-Oppau plant looking north from about
1,200 ft, on 7 May 1945. The older part of the plant is in the foreground and
Oppau in the distance. The Rhine was the most important means of transportation
for this plant, both for raw materials (coke and coal), and many
products.
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Left - Figure 112. Verticalaerial view of Leuna Works, taken by the Luftwaffe in August, 1944.
War History of a Typical Nitrogen and Methanol Plant
Ammoniakwerk Merseburg (Leuna), a typical plant producing ammonia and
methanol (integrated with other chemicals and liquid fuels production), is
located at Leuna near the Saale River. It is over 11,000 ft long, up to 3,500 ft
wide and occupies 757 acres, of which area 23 percent is occupied by buildings
and tanks. The plant produces liquid fuels, ammonia, methanol, and the higher
alcohols, by three basic high pressure syntheses from gases derived from coal,
coke, air, oxygen, and steam. Chemical derivatives from the basic materials
comprise some 80 products including synthetic fuels and lubricants, fertilizers,
acids, various solvents, organic chemicals, plastics, etc. In 1943 the monthly
production of the plant was 21,000 tons of nitrogen, over 14,900 tons of
methanol, and 600 tons of isobutyl alcohol. This was approximately 32 percent of
the synthetic nitrogen and 72 percent of the methanol production of Germany.
Some idea of the size of the plant, may be gained from the following figures. It
aconsumed annually over 1,000,000 tons of by-product coke, 400,000 tons of brown
coal tons of brown coal; gas production in the plant for process and fuel
exceeded 390,000,000 cu. ft. daily; water was consumed a rate of up to 180,000
gpm; the steam generating capacity was 4,300,000 lb per hour and the connected
electric load 390,000 kw (see Figures 111, 112).
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