Vessel engine testers test the performance of vessel engines such as electric motors, nuclear reactors, gas turbine engines, outboard motors, two-stroke or four-stroke diesel engines, LNG, dual fuel engines and, in some cases, marine steam engines in specialised facilities such as laboratories. They position or give directions to workers positioning engines on the test stand. They use hand tools and machinery to position and connect the engine to the test stand. They use computerised equipment to enter, read and record test data such as temperature, speed, fuel consumption, oil and exhaust pressure.