First successes and patents
On 1 November 1881 a patent application was filed for the "Schenck Registration Device", a card printer for steelyards designed by Carl Schenck. A comparison with the card printer invented by the Frenchman Chamcroy reveals that Carl Schenck's machine was the first to allow the weight to be clearly printed on a single line. Once the new invention had been approved for calibration, the first registration devices were dispatched to customers in 1884, with the 100th device being completed in October 1885. The patent was granted on 26 March 1882, in spite of competitors' objections. It was later challenged many times, and was not finally confirmed by the Imperial Court of Justice until May 1887.
The hand-operated steelyard balance with the new registration device brought rapidly increasing sales for the young company.
In the years that followed Carl Schenck devoted his attention to another invention, the automatic steelyard, which would calculate the load without any human intervention. He was hampered by a number of unexpected problems, as the production techniques available at the time could not achieve the precision required for all parts of a legal-for-trade device. After several years of work, it was decided to limit the use of the device to the weighing of narrow-gauge and suspension track vehicles, for which only the deviation from the required weight needed to be calculated. While the minimum load on the balance was permanently counterbalanced on the scales, a single precision balance slide used the maximum load to establish the laden weight of the vehicle. This invention was patented in 1891 under the name "weighbridge with automatic sliding weight".
The first automatic weighing machines for rolling and suspension tracks were delivered in 1890/91. The new automatic steelyard balance, which won a gold medal at the 1900 World's Fair in Paris, quickly made the company's name overseas. In 1898, for example, 13 of these balances were delivered to gold mines in the Transvaal (South Africa) and ten to the Imperial Japanese Steel Works.
In addition to the weighing machines mentioned in the first introductory letter to potential customers, many other devices were developed, including crane scales for larger loads and platform scales for weighing hot steel ingots, destined for the iron and steel industries in Lorraine, the Saarland, Westphalia and Upper Silesia.
Another key development was the locomotive weighing device for measuring axle loads. These devices were shipped not only to locomotive manufacturers but also to numerous railway administrations in Germany and abroad.
Expanding the product range
In 1894 Carl Schenck began to produce material testing machines, which he already had experience of manufacturing in Mannheim. As well as universal machines for drawing, pressing and bending, the company also made spring and chain testing equipment.
As prices fell, competition made train scales more and more difficult to sell. Although this was partly compensated for by rising sales of patented products, Carl Schenck believed it was time to expand the product range. He began by supplying railway administrations with revolving and transfer cranes, turntables and transfer tables. The construction of the new foundry building also required an overhead crane, which Carl Schenck built himself after buying the necessary plans. It was then decided to add overhead cranes to the manufacturing range.
Carl Schenck had attached great importance to the iron foundry from the very beginning. As well as the cast parts needed by the factory, it also supplied brake blocks and axle boxes for the railways, a forge, and cast parts for machinery and construction. These activities had kept the foundry busy for over ten years. To make larger parts, however, especially vertically produced cast-iron pillars, it became necessary to build a new, higher foundry building. Other construction work was undertaken at the same time, including the erection of a new office building, a steam-electric power and light generating plant and a siding that connected to the main railway line. All these new facilities went into operation in 1895.
Because Carl Schenck ploughed his profits back into the company, to improve his designs and equipment, he was able to continuously increase the size of the workforce, from 25 people in 1881 to 186 by 1894.
Looking at the incredible number of new developments during this period, the figures paint a vivid picture of the hard work that Carl Schenck must have invested every day in the operation, development and enlargement of the plant. Managing the commercial staff, designers and workshops and supervising the training of new workers had consumed a great deal of his energies, so he decided to hand over the responsibility for the company to younger shoulders. He made his son-in-law Dr. Georg Büchner and his nephew, engineer Emil Schenck, partners and directors and on 1 June 1894, with an initial capital of 335 000 marks, the three founded "CARL SCHENCK Eisengießerei und Maschinenfabrik Darmstadt GmbH".