The Dogbolter Temporal Rocket was an experimental time machine developed by Intra-Venus, Inc. in 8162. The user wore it on their back and used the left hand control to go back in time, the right hand control to go forward.
Josiah W. Dogbolter advertised it as giving unlimited potential for personal time travel to his shareholders. He employed Death's Head to hunt the Seventh Doctor through time using the prototype, but planned to destroy both with a nuclear bomb built into the device. Death's Head took the Rocket to Thetford in 1646, the early Triassic Period, and the Battle of the Somme in 1916 before finding the Doctor at a Brighton pantomime. He pursued the Doctor into his TARDIS, where the bomb was detected and he realised Dogbolter had betrayed him. The Doctor unlocked the Rocket's clasps and Death's Head left it on the roof of Intra-Venus, Inc. headquarters, where it exploded. (COMIC: Time Bomb!)