"QE2" once again experienced mechanical problems following her annual overhaul in November 1983. Boiler problems caused Cunard to cancel a cruise, and, in October 1984, an electrical fire caused a complete loss of power. The ship was delayed for several days before power could be restored. Instead of replacing the QE2 with a newer vessel, Cunard decided that it was more prudent to simply make improvements to her. Therefore, from 27 October 1986 to 25 April 1987, "QE2" underwent one of her most significant refurbishments when she was converted by Lloyd Werft at their shipyard in Bremerhaven, Germany from steam power to diesel. Nine MAN B&W diesel electric engines, new propellers and a heat recovery system (to utilise heat expelled by the engines) were fitted, which halved the fuel consumption. With this new propulsion system, "QE2" was expected to serve another 20 years with Cunard. The passenger accommodation was also modernised. The refurbishment cost over £100 million.