Tractor Trailer Guided Tours Take a 25 minute guided Tractor Trailer Guided Tour (seating maximum 22 adults per trip) to the 'out of bounds' part of the site. You will see the remains of many of the buildings used in the production of explosives including the Grand Nitrator (where nitroglycerine was manufactured), Newton’s Pool used for the testing of underwater explosives including the explosives used in the Dambusters' “bouncing bomb” and our iconic Press House with waterwheel and press where one of the most dangerous processes on site took place.