Appendix A. Strategic Air Attack on the German Chemical Industry

Nitrogen

Nitrogen⁴ is essential to war. Military powders and high explosives require nitrogen (in the form of nitric acid) for their production. Fixed nitrogen is also vital to agriculture; the Germans considered 2.2 pounds of nitrogen equivalent to 33.1 pounds of cereals. In addition to the large-volume applications of obviously critical military concern, nitrogen plays many secondary, less critical roles in the manufacture of rocket propellants, dyes, lacquers, plastics, rayon, films, drugs, and salts for case hardening of metals.

Sources of German Nitrogen Production

Germany's production of nitrogen compounds was derived from three sources:

1. Synthetic ammonia, made by the Haber-Bosch high-pressure synthesis. This process uses a gaseous mixture of atmospheric nitrogen and hydrogen prepared either by purification of producer gas and water-gas derived from the basic raw materials, coal, air and water, or as in the Ruhr synthetic plants, by fractionation of gas from coke ovens.
2. Calcium cyanamide, manufactured by passing atmospheric nitrogen over heated calcium carbide derived from coal and limestone.
3. By-product ammonia, recovered from coke-oven gas and used largely in fertilizers as ammonium sulfate.

Prewar Development of Germany's Nitrogen Industry

Germany pioneered in synthetic ammonia just prior to and during World War I, and has since held an increasingly strong position in its production. Table A1 shows the development of her nitrogen production before World War II.

* 1913-1924 data from U.S. Bureau of Foreign and Domestic Commerce. Trade Information Bulletin 605, page 13.
# Fertilizer year, 1 June to 31 May. Unless otherwise noted, all following statistical data in this section are based on this "fertilizer year"

Stocks and Exports

In 1929, Germany was exporting 250,000 tons or over 30 percent of her production annually. In the fertilizer year 1938-39, nitrogen production was allocated approximately: 78 percent (745,000 tons) to agriculture, 11 percent (105,000 tons) to industry and 11 (106,000 tons) percent to exports (see figure 2).

Germany entered World War II confident that her large production capacity for synthetic ammonia, calcium cyanamide, and by-product ammonia would adequately meet nitrogen needs of expanded powder and explosives manufacture and of agriculture. The raw materials mobilization plan of July, 1939, stated that the mobilization requirements for concentrated nitric acid of 23,000 tons per month for the Army plus 4,500 tons per month could be fully met by domestic production for a "practically unlimited" time. Therefore no appreciable stocks of fixed nitrogen were accumulated.

Plant Location and German Production

Figure 1 shows the geographical location of these nitrogen plants and those built during the war.

Significantly, more than 50 percent of prewar synthetic production was concentrated in the Leuna plant. Both Leuna and Oppau, the largest plants, were integrated plants producing aviation gasoline and methanol as well as ammonia.

Germany's War Plans and Their Realization

Under the Goering four-year plan and later revisions, synthetic nitrogen capacity was further increased by two new plants, Heydebreck I and Linz I, with ultimate planned capacities for 1944-45 of 94,000 and 47,000 tons per year, respectively, and by expansions at Oppau of 100,000 tons per year and in the Ruhr plants of 36,000 tons per year. Additional capacities were to be realized after 1943 in three more plants, Heydebreck II (16,000 tons per year), Linz II (42,000 tons per year), and Koenigshuette II (14,000 tons per year). Cyanamide capacity was not increased.

Figure 2 shows German plans of September, 1942, for nitrogen production and utilization during the war; for comparison, actual figures are shown for the period after 1 June 1942. This plan was revised in March, 1943.

Table A3 compares the plan with capacity available and with production.

* After available nitrogen capacity diverted to production of fuels, methanol, and ethylene had been discounted.
# Total available nitrogen capacity, including the facilities diverted to other products.

After 1942, production fell short of plans because of (a) delays in the construction of the Heydebreck I plant, and difficulties in its operation, (b) cancellation of the construction project for three large plants (Heydebreck II, Koenigshuette II, and Linz II), (c) loss from air attacks, (d) a shift in production at Leuna from synthetic ammonia to methanol and aviation gasoline, and (e) the sacrifice of cyanamide in favor of ethylene, as shown in Table A4.

Effects of the Combined Bomber 0ffensive

The heavy, repeated attacks did not begin until May, 1944. Figure 3 shows the over-all nitrogen production by processes from the middle of 1943 to May, 1945. It also shows production of synthetic nitrogen for the same period at Leuna, at Oppau, and in other synthetic plants. Table A5 gives the monthly synthetic nitrogen production for each of the more important plants and the total synthetic production with dates of air attacks. The first dip in the German production curve in late 1943 resulted from the effects of the first bombing attacks on Oppau superimposed upon the normal seasonal slump in calcium cyanamide production. This slump came about from curtailment of carbide production when power was diverted to winter demands. Production recovered completely and was as high in March and April, 1944, as it ever had been previously (Figure 3). From the beginning of the attacks on oil plants in May, 1944, nitrogen production plummeted in January, 1945, to about 11 percent of April's production; 95 percent of the synthetic nitrogen production was lost.

* Plant Production figures for 1943 are gross production without deduction of allocated processing loss
# Includes Ewald, Knurow, Koenigshuette (Ostmark Stickstoffewerke A.G.), Aussig, Rhina, and Brabag-Wacker

Calcium cyanamide production suffered more effects from indirect effects than direct bombing. An exception was the plant at Knapsack, which lost its night carbide production for three months as a result of an attack in April, 1944, which blew off the roof, making a blackout impossible. It was attacked again on 29 September and lost its entire production after 21 October, when the Goldenberg power station was destroyed. The total loss of nitrogen from this plant to January, 1945, was about 5,500 tons. By-product nitrogen held fairly constant until October, 1944. The exact proportion of the loss from air attacks thereafter could not be ascertained, but the main losses resulted from destruction of the western and Upper Silesian plants beginning in December.

Total losses of nitrogen production as a result of bombing are shown in Table A6. Actual production of nitrogen during the period 1 May 1944 to 1 April 1945 (363,500 tons) was less than planned production as of 5 May 1944 (973,600 tons) by 610,100 tons. Of this loss, 79 percent (480,800 tons) is directly attributable to air attacks on Leuna (222,600 tons), Oppau (136,200 tons), and other producers (122,060 tons).

* Figures from 1 May 1944, based on plan of 5 May 1944.
# Estimates.

Figure 4 shows the loss from the monthly planned production, according to the last long-range plan, that of 5 May 1944. The monthly total weight of bombs dropped in all nitrogen plants as part of the oil offensive is shown in Table A7 and graphically by month at the top of Figure 3. Table A8 gives the loss of nitrogen expressed in metric tons lost per short tons of bombs dropped.

* From Tabulating Section (International Business Machines) data.
# As compared to plan of 5 May 1944 (Figure 4).

* As compared to planned production as of 5 May 1944.
# From Tabulating Section (IBM) data.
° Based on ratio of HE bombs to total bombs for period of 1 May 1944 to 30 April 1945.

Production and Production Loss in Occupied Countries

Until the beginning of 1944, Germany relied on nitrogen production from the occupied countries for about 30,000 tons per month, nearly 38 per cent of Germany's total production, as shown in Figure 5. The western countries, France, Holland, and Belgium, contributed generally from 20,000 to 25,000 tons per month, and, according to the production plan for the second quarter of 1944, they were to produce about 29,350 tons per month. But production fell sharply in the two months preceding D Day, to 17,000 tons in April and to 11,000 tons in May. Figure 5 indicates the further drop that followed D Day.

Out of the April-May loss of 30,700 tons, 5,500 tons or 18 per cent were lost as a result of three air attacks and the resulting shutdown of three plants: in France, Chocques (attacked 11 September 1943) and Toulouse (attacked 1 May 1944), and in Belgium, Renory (attacked 11 May 1944). The remainder of the loss was the result of coal and power shortages, partly because of sabotage and other underground action.

Effects of Nitrogen Production Loss on Armaments and Agriculture

The drastic effects of air attacks on nitrogen plants are illustrated in Figure 6.

In order to supply the expanding powder and explosives industry, agricultural requirements were sacrificed to increase the allotments to explosives. In 1939-40 and 1940-41, German agriculture received 95 percent of the 1938-39 consumption, plus supplementary allocations for special groups in 1939-40 only. The ration was reduced stepwise to 80 percent in 1941-42, 72 percent in 1942-43, and 54 percent in 1943-44. The sharp drop in nitrogen production in May 1944, was reflected within two months in shortages of nitric acid and extenders for explosives. From then to the end of the war, the Germans were forced to take increasingly more drastic action to stretch the shrinking nitrogen supplies. All deliveries of synthetic ammonia to agriculture were stopped in August, 1944, and the small saving diverted to powder and explosives. Stocks, accumulated mostly in the form of fertilizers, were sharply reduced (see Figure 5). Stocks of sodium nitrate (1,600 to 2,300 tons nitrogen), German and Italian calcium nitrate (9,000 tons), and the mixture of ammonium nitrate and calcium carbonate (5,000 tons) were recovered from fertilizer stocks and used directly, or after processing, as explosives extenders, though much inferior to the ammonium nitrate normally used. By-product ammonia was converted to nitric acid. Ammonia was even recovered from by-product ammonium sulfate production and fertilizer reserve stocks and converted to nitric acid. TNT was recovered from UXB's, obsolete ammunition shell fragments, and floor sweepings. But not even these extreme emergency measures did not stop the decline. As a result, available shells could not be filled, and so an inert dilutent, rock salt, was added in increasing amounts (up to 70 percent) to the TNT used in filling mines, grenades, and shells. After September, 1944, in the last months of the war, general ammunition shortages were reported.

Conclusion

Allied air attacks directed at Germany's synthetic oil plants effectively destroyed Germany's nitrogen production with disastrous results to its munition manufacture. Had the total bombing effort expended on many targets in the fall of 1943 been concentrated on the few synthetic ammonia plants, Germany could have been knocked out of the war much sooner.

Methanol

Production and Use

Methanol (wood alcohol), originally produced by wood distillation, is now synthesized from water-gas produced from coke and steam. The production process, equipment, and raw materials are practically identical with those of ammonia synthesis. The only significant difference is that in ammonia synthesis carbon monoxide must be removed from the nitrogen and hydrogen, in a step not required for methanol.

With a slightly modified catalyst the methanol process may yield isobutyl alcohol, raw material for the manufacture of aviation gasoline. The location of existing and planned facilities are shown in Figure 7.

The annual production of methanol in Germany during prewar and early war years follows:

The production records and information gained from questioning German industrialists revealed methanol's importance to the German war effort. Table A9 shows the production and allocation made to major consuming industries based on a plan made in October, 1942; the planned production is also shown in Figure 8. Dispersing production reduced the hazard of depending only on the plant at Leuna.

Adequate expansion was provided to meet the increasing demands, and considerable flexibility was inherent in the interchangeability of ammonia, isobutyl alcohol, and methanol production. The requirements are indicated graphically in Figure 9, and production, stocks, and allocations are shown in Figure 10.

Table A10 shows that production was substantially as planned in 1943, 47 percent in 1944, and only about 10 percent during the first three months of 1945.

Effects of Bombing on Production

The effects of the bombing of Oppau during the winter of 1943-44 were even more disastrous to methanol than to ammonia production. There was no production on 134 days out of 176 days during the period. From May, 1944 to April, 1945, inclusive, 32,000 tons of bombs were dropped on Leuna and Oppau, which together had produced 52 percent of Germany's methanol. This resulted in the loss of 163,000 tons, or 40 percent, of the planned production for the period.

The methanol plants at Auschwitz and Heydebreck, starting operations in the fall of 1943, had come to the rescue, but were themselves bombed beginning July, 1943. From 1 July to 31 December 1944, 4,800 tons of bombs were dropped on Auschwitz and Heydebreck, causing a loss of 62,000 tons or 30 percent of the planned production for the period.

The effects of bombing on methanol production are shown in Figure 11. Production of isobutyl alcohol at Leuna and Oppau together was greater than their methanol production, and was similiarly affected.

Changes in Planning as a Result of the Air Offensive

As a result of the air offensive, drastic revision of allocations to the various industries was necessary. This principally affected industries which were related on indirectly to the war effort. The explosives industry also suffered, but obviously this had high priority. However, supplies of methanol used in the production of tolulene and in chemical warfare were drastically reduced. Also a cut was made in the allocation to the rubber industry, which was already suffering from a shortage of raw materials as a result of the bombing offensive. The manufacture of hexogen was also curtailed. This directly resulted in munitions containing reduced quantities of high explosives; it has been more fully discussed in the section on explosives in the Oil Division report.

Toward the end of 1944, it was planned under the Geilenberg program to convert from nitrogen to methanol production in two small plants, namely, Fuerstenberg-on-Oder, and Linz, in May, 1945. A plant designed for production of 2,000 tons per month of methanol from gases from carbide overn was scheduled to start in May, 1945 at Schkopau. Similiar small emergency plants were under construction for Piesteritz, Fuerstenberg, and Trostberg, but did not materialize before the occupation.

Calcium Carbide

Importance and Use

Calcium carbide was of great importance in the peacetime economy of Germany, the industry averaging 63,000 and 88,000 tons per month in 1938 and 1939, respectively. Manufacture of calcium cyanamide, used as fertilizer, took 50 percent of the total peacetime output. The remainder went into the manufacture of rubber, granulated carbide, solvents, plastics, and through acetylene made by treating calcium carbide with water, a wide range of miscellaneous products.

Raw Materials

The production of calcium carbide requires large amounts of electric power and two raw materials, limestone and coke. Both are plentiful in Germany. Electric power is the principal item of cost (60 percent).

Plants

The calcium carbide manufacturing plants were widely dispersed throughout Germany, as will be seen by reference to Figure 12. Although 90 percent of total production was in 10 of 21 producing plants, the industy was not so concentrated as to be particularly vulnerable to air attack. Plants were necessarily located close to sources of power in the following regions:

1. The lignite mines of central and western Germany.
2. The bituminous coal deposits of the Ruhr and Upper Silesia.
3. The water power from the slope of the Alps in southern Germany.

The ten major plants, with the planned production for 1944, are shown in Table A11.

Planning for War

In Table A12, the average monthly production of calcium carbide to January, 1944, indicates the development of the industry.

Details of production by plants from 1943 through March, 1945 are shown in Figure 13. The planned and actual production for Germany and occupied countries and allocation for the same period are shown in Figure 14.

The year 1942 is typical of consumption of carbide during the war years. Table A13 gives monthly average quantities.

The fluctuation between 146,000 tons per month and 107,000 tons per month in the period from the summer of 1943 to March, 1944, resulted in seasonal variations in the supply of coal and water power, and not from direct air attacks.

Effects of Bombing on Production

German carbide plants were not specifically attacked. However, their production was reduced by the air attacks on outside electric power plants and by attacks directed primarily at oil targets (Auschwitz and Schkopau) which also produced carbide.

From the 1944 high in July of 138,000 tons, production declined steadily to 41 percent of the 1944 high, 57,000 tons, in February, 1945 as a result of air attacks on Knapsack, Schkopau, Ludwigshafen, and Auschwitz, and on transportation and power plants. Production never attained the 160,000 tons per month planned in the summer of 1944.

Knapsack (A.G. fur Stickstoff-Duenger), which produced about 17 percent of the total German carbide, was bombed late in April, 1944, possibly in an area attack. Inquiry revealed that the roofs over the carbide ovens were blown off; this caused slight loss and required shutting down for blackouts. On 21 October the Goldenberg power station, source of Knapsack's electric power, was eliminated by air attack, causing the shutdown of carbide production. Operation was not resumed until December, 1944, and then on a small scale - 4,500 tons in January, 1945, as compared to a normal production of 24,000 tons per month.

At Schkopau the biggest and newest plant was designed to produce 28,000 tons per month, or 20 percent of the total German planned production of calcium carbide. Its output had to be reduced materially, because the requirements for Buna rubber manufactured at Schkopau were curtailed as the result of bombing on Leuna, which supplied Schkopau with necessary hydrogen.

The air attacks on Schkopau at the end of 1944 (21 and 25 November and 6 and 12 December) contributed to the drop in production throughout the period. The carbide installation was badly hit during the raid of 25 November. Schkopau's carbide production dropped from 26,000 tons in April, 1944 to 6,000 tons in December, 1944, a loss of about 15 percent of the total German carbide production in July, 1944.

Conclusions

In spite of the importance of calcium carbide in the German war economy, the full capacity of the industry (amounting to 1,900,000 tons per year in 1945) could not be utilized, primarily because of a shortage of power, congestion of transportation facilities, and a limited offtake of products as a result of strategic bombing of consuming plants. The calcium carbide industry, while never subjected to direct attacks, suffered indirectly. There is no evidence that Germany suffered through the shortage of carbide or that it should have been made a priority target.

Sodium Cyanide

Importance and Uses

Sodium cyanide, together with hydrocyanic acid, gained industrial importance in this war, particularly as a result of its use for Plexiglas, a transparent a plastic for which there is no present substitute in aviation. Other uses were in case-hardening agents, electroplating salts, insecticides, and chemical warfare.

Raw Materials

The I.G. process utilizes ammonia, carbon monoxide, and sodium carbonate. These raw materials were not critical, since this process consumed only a small fraction of their total production. The Degussa process utilizes ammonia, charcoal, and metallic sodium. This last was made in only two plants in Germany, and failure in its supply would seriously hamper sodium cyanide production.

Plants

Two plants produced about 75 percent of Germany's cyanide: the I.G. plant at Ludwigshafen, operating with the formamide process with a montly capacity of about 900 tons, and the Degussa plant at Frankfort, using the Castner process, with a capacity of about 500 tons monthly. A small plant at Piesteritz, using the Aerobrand process, and two small plants at Dessau and Kolin where cyanide was recovered as a by-product of molasses refining, accounted for most of the remaing production.

Status of the Industry Before Bombing

Actual and planned production are shown in Figure 15. At the beginning of 1941, production was approximately 10 percent in excess of requirements of 1,100 tons per month. But requirements increased rapidly to about 1,800 tons per month at the beginning of 1944, and plans were made to raise production capacity to 1,400 tons per month in the first half of 1944 and to 1,800 tons per month in the second half. Production, however, remained substantially constant at about 1,250 tons per month through 1941 and 1942, and decreased somewhat through 1943, averaging 1,150 tons per month for that year.

All exports were stopped at the end of 1943. A few hundred tons per year of imports were received from Holland, and a total of about 300 tons through the first three years of the war from France.

Effects of Bombing on Production

Though bombing attacks were never directed specifically at sodium cyanide production, a considerable production loss can be attributed to bombing. This resulted principally from attacks on Ludwigshafen, with synthetic oil production as the objective, and from area attacks on Frankfort, in which the Degussa plant was hit.

As seen in Figure 15, a sharp drop in production occurred in early 1944 as the result of several events. Unusually cold weather froze the pipe line which supplied Ludwigshafen with carbon monoxide gas from the Saar; an air attack on the Ludwigshafen plant on 7 January shut down formamide production for some time; and at the end of January, an attack on the Frankfort area badly damaged the Degussa plant. These events practically eliminated production from Germany's two main plants in February, bringing total production for that month down to 250 tons. This was considered "catastrophic" by the German authorities, and its effect was an immediate drop in supplies to the Army.

A further attack on Frankfort occurred on 22 March and kept Degussa's production down through April. Thereafter the Degussa production increased, reaching 500 tons in July. In spite of difficulties, total production rose in July to over 1,200 tons, more than the 1943 average, but appreciably below the July planned production of 1,900 tons. By this time stocks had been practically exhausted, except for an Army reserve of about 2,500 tons.

After July, production declined rapidly to only 150 tons in January, 1945. This decline was caused by:

1. Heavy damage to the Frankfort plant from an attack of 12 September 1944, forcing makeshift operations only; and
2. The elimination of Frankfort's source of sodium metal, the Degussa Knapsack plant, as a result of attacks on the near-by Goldenberg power station, which not only cut off the electric power for Knapsack, but damaged the plant itself. On 21 October 1944, 150 bombs fell in the plant. Except for a small makeshift production (130 tons in the last quarter of 1944), the Frankfort plant was shut down after October. This small production may have been made possible by the use of sodium from the other source available, Gersthofen, the I.G. Castner sodium plant.

There is no indication that the slight reduction in production of Kolin and Piesteritz between July, 1944, and the beginning of 1945 was the direct result of any air attack.

Substitute and Emergency Plans

Because of the imminent collapse of the chemical industry in Germany, plans for reconstruction or dispersal of a monthly output of about 400 tons were not completed at the end of the war. Degussa had planned in the early part of 1944 for the auxiliary production of cyanide at Knapsack, but the attacks on that plant and tbe destruction of its source of power prevented these plans from being carried out.

Conclusion

Sodium cyanide production was largely concentrated in two plants, and a large proportion of the production went directly into critical supplies; further, there was little excess production capacity over requirements even at the start the war. For these reasons, the industry have been rated high as a strategic bombing target. However, it was less critical that synthetic oil and nitrogen and should have had a priority below those of synthetic oil and nitrogen.

Ethylene and its Derivatives

Importance and Uses

The industry based on ethylene chemistry in Germany was comparatively new, and its products were largely used for war purposes. As shown in Figure 16, about 65 percent of Germany's ethylene production was converted into ethylene oxide, 15 percent was used in making styrene (for synthetic rubber), 13 percent was used for making synthetic lubricating oil, and 7 percent went into miscellaneous uses. Figure 17 indicates that 60 percent of the intermediate product, ethylene oxide, was used to make ethylene diglycol (to be converted into diglycol dinitrate, a propellants explosive); 30 percent to make glycol (used principally as anti-freeze); and 10 per cent went into miscellaneous uses. Thus an exceptionally large proportion of the output of this industry had important military uses, and only a small civilian consumption was available for diversion to vital uses to compensate for any loss of production.

Raw Materials

While the primary raw materials for ethylene are coal and limestone, as in the case of most German chemicals, ethylene is not prepared directly from these, but from intermediate products of other chemical processes. Several ethylene processes are employed in Germany, each requiring different raw materials. The total planned capacity in Germany at the end of the war was 12,635 tons monthly, divided, according to raw materials required, as follows:

Thus ethylene production depended for its raw materials mainly on other industries, themselves subject to destruction by bombing.

Plants

Effects of Bombing on Production

Stocks of ethylene and ethylene oxide always quite small, and therefore the consumption data shown in Figures 16 and 17 indicate production quite closely. Ethylene production averaged about 7,300 tons monthly in 1943, rose to over 8,000 tons monthly in the spring of 1944, and dropped to only 5,500 tons in October. Data are not available for later months, but production continued to decline with the general deterioration of German industry. Ethylene oxide production evidently enjoyed the highest priority, because its production, though generally, following that of ethylene, does not show so marked a decline. Ethylene diglycol was given the highest priority for ethylene oxide supplies, with the result that the production of diglycol never declined materially; the October production of 3,500 tons was almost as large as that of month earlier in the year.

In Table A14 the production for October, 1944, of ethylene and ethylene oxide is compared with the maximum production attained in March of the same year, and the causes of the production losses are explained. Of the 3,100 tons per month decline in ethylene production, 2,000 tons per month were the result of air attacks on Leuna, Holten, and Ludwigshafen. These were bombed, not as chemical targets, but because of their synthetic oil production. Thus the principal loss of ethylene production was a by-product of the oil-target bombing, and nearly half the decline in ethylene oxide production resulted from the same cause.

The largest ethylene plant (Gendorf) was never bombed. In the next two largest plants (Huels and Schkopau) production did not suffer materially from bombing attacks. During October, 1944, these three plants produced 90 percent of their March output and accounted for 87 percent of the country's production. Thus, in spite of the fact that production stopped in Leuna after May, in Zweckel after July, and in Ludwigshafen and in Holten after August, 1944, the over-all effects of air attacks on ethylene plants was not great.

However, the industry suffered indirectly from air attacks which deprived it of its raw materials. In October, 1944, unharmed capacity of about 10,000 tons was available, but actual production was only 5,500 tons. The remaining capacity was idle, principally for lack of raw materials. The capacity utilizing acetylene was idle because carbide was unavailable, and also because the bombing of Leuna deprived Schkopau of its hydrogen supply. Oil plant and coke-oven gases were not available for the plants utilizing these. Plants using alcohol ran closer to capacity, but they, too, apparently suffered from some shortages in raw materials.

Conclusion

Production of ethylene and its derivatives was concentrated in a few plants, of a type quite vulnerable to attack. A large proportion of the output went into products the loss of which would have hurt the German military effort directly. Stocks were always low. Despite these factors, ethylene apparently was less critical to the Germans than oil and nitrogen, and hence should not have top bombing priority, except where located in oil or nitrogen plants.

Tetraethyl Lead

Importance and Uses

Tetraethyl lead was unique in the German war economy. While the volume of its production (400 tons per month) was only a drop in a bucket, its direct importance to the Wehrmacht and Luftwaffe ranked it among the most valuable chemicals.

Tetraethyl lead is the active ingredient of ethyl fluid (called Fluidin in Germany) which in used to improve the performance of aviation gasoline. Without ethyl fluid, the "performance number" of German aviation gasoline would have dropped from 150 to approximately 90, and the power output of their airplanes would have dropped in about that ratio. A gasoline-fueled plane engine, originally able to deliver 2,000 hp in the pinches, without tetraethyl lead could deliver only about 1,200 hp. Since the use of tetraethyl lead requires the addition of a corrective agent, ethylene dibromide, both these materials will be considered simultaneously.

The Germans made an aviation ethyl fluid of the same composition as that made by the United States (one molecule of ethylene dibromide per molecule of tetraethyl lead) and used it in about the same concentration.

The basic raw materials, lead, salt, alcohol and bromine, were all readily available in Germany. Two of the intermediates, metallic sodium and ethyl chloride, had little other use; therefore, curtailment of their production would directly affect tetraethyl lead.

Plant Location and German Production

Germany had only one ethylene dibromide plant located in Tornesch near Hamburg. This had sufficient capacity to take care of requirements, and its production was adjusted to correspond to tetraethyl lead. Failure of ethylene dibromide production in October and November, 1943, was caused by an accidental fire, and production thereafter was accelerated to make up the deficiency. In spite of this vulnerable position, Germany apparently never considered the construction of a second ethylene dibromide plant.

Two prewar plants made tetraethyl lead in Germany: one at Gapel near Berlin, with a capacity of 100 tons per month, and one at Frose, near Magdeburg, with a capacity of 300 tons per month. Gapel was a peacetime plant built in 1936, whereas Frose was built secretly in 1938 to take care of wartime requirements.

In the early stages of the war, capacity was insufficient to keep up with the expected increase in requirements. For this reason, and also to protect a vital industry, plans were made for construction of two additional tetraethyl-lead plants. A third plant, as large (400 tons per month) as the other two existing plants together, was to be built in Heydebreck (Upper Silesia). Its planned completion date was January, 1945. Actually, when the site was occupied by the Russian Army, the plant was nearing completion, but had never been in production.

As part of the general plan for dispersal of industry, a 200-ton-per-month underground plant was projected in September, 1944, to be erected in a natural cave near Brixlegg in the Austrian Tyrol. The completion date planned was February, 1945, but by April, 1945, the work completed had hardly prepared the site.

The Germans also used, beginning in March, 1942, the French tetraethyl-lead plant at Paimboeuf, in spite of its vulnerable position on the Atlantic coast. It had a capacity of 200 tons per month, but operating difficulties, primarily passive resistance by the operating staff, kept production down to 26 per cent of capacity.

Production Records

Complete production records for the German plants are not available, since the Gapel plant was in the Russian occupied zone. Table A15 gives monthly production figures approximated from the few records available. The two German plants were kept operating at full capacity as long as possible. Beginning in May, 1944, Gapel experienced difficulty in securing supplies of coal and ethyl chloride. Beginning in August, 1944, Frose production dropped for lack of ethyl chloride, as a result of the bombing of Ludwigshafen-Oppau and Leuna.

* Production figures for Gapel are based on interrogations.
# Production figures for Frose up to August are approximations based on perusal of plant records.
¶ Figures from August through December, 1944, are actual, from plant records.
** Estimated.
## Cutback caused by a shortage of coal.
*** Plant damaged by accidental fire.
### Cutback caused by a shortage of ethyl chloride shipments.

Effects of Bombing on Production

The anticipated requirements, production, consumption, and stock position of Germany are given in Table A16. Consumption closely approximated production, and the stocks remained substantially constant with a backlog of about 6 months' consumption until March, 1944, when consumption began to exceed production. After July, 1944, decline in production showed the effect of the bombing of the ethyl chloride plants supplying this raw material. The slight increase in stocks after August, 1944, was not due to an increase in tetraethyl-lead production, but rather to the fact that the production of gasoline (and hence the use of tetraethyl lead) was deteriorating even more rapidly.

* At first of month.
# Figures in this column do not check exactly with those given in Table A15. They are believed to represent shipments from the plants rather than actual production.

This industry was particularly vulnerable to air attacks. Both tetraethyl lead and ethylene dibromide plants handled highly reactive and inflammable materials. Both used special equipment which would take several months to replace. Part of the ethylene dibromide equipment was very fragile. Germany depended entirely on only three small plants for its total requirements.

The industry was never attacked specifically. A few bombs were dropped on Gapel once, as a secondary target, but no damage resulted. The industry nevertheless felt the impact of the air offensive, and had to cut back production for lack of necessary raw materials.

Sulfuric Acid

Importance and Uses

Sulfuric acid is a fundamental industrial chemical essential in the war and peace economy of any industrial nation. So varied and important are its uses that its production is a reliable index of business conditions. In peace a substantial part of the German production of sulfuric acid went into phosphate fertilizer; the war interrupted imports of phosphate and this considerable production of sulfuric acid was then used for war purposes. Consumption during the earlier years of the war was distributed approximately as follows: explosives 12 percent, nitrate fertilizer 21 percent, artificial fibers 23 percent, other uses 44 percent.

Raw Materials

In peacetime 75 percent of the sulfur used in sulfuric acid production was imported as crude sulfur and pyrites. As the war progressed, measures were taken to utilize indigenous low-grade pyrites, by-product sulfur from gas purification in hydrogenation plants, and even gypsum by a war emergency process. Domestic raw materials thus constituted 62 percent of the total raw materials used in sulfuric acid production in 1941, and undoubtedly rose to a higher percentage later.

Plants

About one third of German's productive capacity, which was about 2,000,000 tons per year (metric tons of sulfur trioxide are used throughout) was in 51 chamber plants, and two thirds in 36 contact plants. As shown in Figure 19, these units were located in all areas of Germany. About 40 percent of the capacity was in the Rhineland, with a lesser concentration in central Germany. Five plants accounted for 31 percent of the total capacity. It was a characteristic of this industry that extremely low stocks were carried, sufficient for only a few days' consumption.

Effects of Bombing on Production

As shown in Figure 20, Germany's wartime production averaged about 170,000 tons monthly until the middle of 1944. In addition, about 50,000 tons monthly were available from France and other occupied territories. Beginning in July, 1944, production dropped steadily to about 75,000 tons by February, 1945, or to 45 percent of its previous level. This loss may be attributed to causes as follows:

Conclusion

Sulfuric acid was highly essential, and no stocks existed to offset loss in production. However, the industry was dispersed among many plants, and an appreciable portion of normal production went into only moderately critical uses which could be eliminated in order to supplement the supply for vital uses. For these reasons sulfuric acid plants did not rate top priority as bombing targets.

Caustic Soda

Importance and Uses

Caustic soda is employed in many wartime and peacetime industries. Its importance was indicated by the high priority accorded it in the allocation of German coal. Until the collapse of German industry beginning in July, 1944, caustic soda consumption in Germany was distributed approximately as follows:

Raw Materials

Caustic soda is made by two processes. The electrolytic process, in which chlorine is a co-product, requires only common salt and coal (for electric power generation). In the lime process, the raw materials are limestone and sodium carbonate; the latter, in turn, requires only common salt, limestone, and coal for its manufacture. Thus, by either process, caustic soda required only raw materials abundant in Germany.

Plants

As shown in Figure 21, the manufacture of caustic soda is widely distributed, some concentration of plants being in central Germany and in the Rhineland. At the end of 1944, 32 electrolytic plants had a capacity of 645,000 tons and 9 causticizing plants a capacity of 292,000 tons per year, making a total capacity of 937,000 tons per year. The three largest plants accounted for 27 percent of the total. Normal stocks of caustic soda were not large, equaling about ten days' consumption.

Effects of Bombing on Production

Production, as shown in Figure 22, increased steadily from about 35,000 tons monthly before the war to about 60,000 tons monthly in 1943 and the first half of 1944. In addition, occupied territories supplied about 12,000 tons monthly. Plans to increase the German production to 87,000 tons monthly in 1944 and 105,006 tons in 1945 were never realized. Production began to drop sharply in August, 1944, and decreased to about 28,000 tons in January, 1945. Little of this decline can be attributed to direct bombing damage. The main causes were lack of power and transportation, and general disruption of industry.

Conclusions

Although of unquestioned importance in Germany's wartime industry, the production caustic soda was widely dispersed, and it had a variety of uses, some of which were only semicritical. For these reasons the industry should not have top priority in strategic bombing.

Chlorine

Importance and Uses

Chlorine is important in the peace and war industries of any industrial country. Until the last months of the war, the consumption in Germany was distributed as to uses: approximately 33 percent for direct Army uses (explosives, anti-freeze and chemical warfare), and the remainder for industrial uses (solvents, paper and cellulose, organic chemicals, plastics, inorganic chemicals, metallurgy, etc.).

Raw Materials

Chlorine is a coproduct with caustic soda from the electrolysis of common salt. The only raw materials required, therefore, are common salt and coal or other source of power.

Plants

Chlorine, as shown in Figure 23, was made in 37 plants well distributed over Germany, the greatest concentration being in the Leipzig area of central Germany. The two largest plants account for about one fifth of the total.

Effects of Bombing on Production

Production rose steadily, as shown in Figure 24, from 22,000 tons monthly in 1938 to about 41,000 tons monthly in 1943. In that year about 5,000 tons monthly were available from France and other occupied territories. German production was maintained at the 1943 level until August, 1944, when a steady decline brought the figure down to 23,000 tons in January, 1945. Only a minor portion of this loss can be attributed to direct bomb damage. Perhaps the most important cause was the shortage of electric power and the many indirect effects of the bombing offensive which broke down Germany's industry generally.

Conclusions

Though of a wide importance in many industries, chlorine does not appear to have been a particularly critical item to Germany. Further, production was relatively well dispersed in many plants. Therefore, the industry was not a strategic bomb target of high priority.

Sodium Carbonate

Importance and Uses

Sodium carbonate is basically important in both wartime and peacetime industries. Large parts of the production are used in making caustic soda, glass, soap, and sodium nitrate fertilizer, and in refining alumina.

Raw Materials

Nearly all of the German production comes from the Solvay ammonia process, which consumes only common salt and limestone. Considerable coal is also required for power and heat.

Plants

As shown in Figure 25, Germany's sodium carbonate production was concentrated in a few plants. At the end of 1944, 14 plants had a total capacity of about 155,000 tons per month. The largest of these, at Bernburg in central Germany, had a capacity of 37,000 tons monthly, about 23 percent of the total. The four largest plants accounted for 58 percent of the total.

Effects of Bombing on Production

Germany's production rose, as shown in Figure 26, from about 90,000 tons monthly before the war to 135,000 tons monthly early in 1943. Supplies of about 30,000 tons monthly weree also available from France and other occupied territories. In July, 1944, the German prodution was 130,000 tons, but thereafter dropped precipitously to only 20,000 tons in February, 1945. An undetermined part of this decline is attributable to direct bomb damage to the Rheinberg, Koeln-Kalk, Duisburg, and Heilbronn plants. Loss of the Hohensalza plant in the east contributed to the loss, but the greater part of the decline is attributable to lack of coal and power, shutdown of consuming industries, breakdown of transportion, and other factors in the general deterioration of German industry that occured at this time.

Conclusions

Sodium carbonate was essential to many German industries and its production was concentrated in a few plants. However, much of the production went into only semicritical products, the loss of which would not quickly affect the German military effort. Therefore, this industry did not have a top priority in strategic bombing.