The locomotive has a maximum tractive effort of "up to" , and a power rating of in electric mode. These figures exceed those of the diesel-powered
British Rail Class 66. It is fitted with the
AWS and
TPWS safety systems, and is planned to be fitted with
ETCS. It has cameras providing views of the pantographs, shunting zones and the front of the locomotive.
Diesel performance The Class 99 locomotive has a 16-cylinder
Cummins QSK50 engine installed, which meets
Stage 5 emissions standards. The locomotives are expected to use
HVO biofuels in service, and will be able to raise and lower their pantographs while moving. Peter Dearman, an expert in traction electrification, reported in
Rail Engineer in early 2023 that the Class 99 may only be able to deliver at the rail in diesel mode. However, this was before the first production locomotive was exhibited at
InnoTrans in September 2024. The chief executive of GBRf, John Smith, reports that the Class 99 will outperform the Class 66 at low speeds, despite having a less powerful diesel engine. The greater tractive effort means that the Class 99 on diesel power can deliver more power at the rail than the 66. The less powerful diesel engine is also not expected to change its use cases, and will be deployed on heavy haul routes and intermodal trains. ==Planned use==