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Album: German Submarines
Image: 297 / 473
Date: 2010-04-15 15:57:02
Tags: Bremerhaven, Germany, Submarines, Type XXI, U 2540

Electric Machines

From originally two electric machines (main traction motors) only one still exists (opposite the exit). These machines were developed by Siemens under the code word "Hertha" (christian name of the director's secretary) using their experience in large train engines.

It is a 10 pole, separately excited shunt-wound motor with auxiliary series winding, interpole winding and compensating winding arranged as a double-unit engine (2 rotors on each shaft). The machines have a weight of 10330 kg each. Two ventilation fans each are fixed on the main traction motors. These are connected to the air coolers in the bilge and provide for heat evacuation.

Under test stand conditions the main traction motors attained an output of 1840 kW for one hour at a voltage of 360 V and current input of 5500 A.

Gear reduction of main traction motors was made by a large toothed-wheel gearing installed under the control platforms.

For silent routine purpose two so-called silent motors are still existing, which were connected with one shaft each through a multiple V-belt drive. (Shown on the right side of exit stairs).

These electric motors were developed by Siemens, too. The externally excited 8-pole shunt motors can be energized with 120 V or 360 V. At 360 V and current input of 256 A they attain an output of 83 kW.