It's been a legal requirement for the brake to be operative throughout a passenger train since the nineteenth century. However, the great and good Peter Olver of HMRI took a very pragmatic view on this and agreed to many a railway using locos where application of the train vacuum brake did not apply the loco brake. From a recent conversation with a HMRI Inspector, this approach, even thougfh technically illegal, will continue to be applied as long as the train brakes will satisfactorily stop a complete train plus loco in an acceptable distance. As a slight aside, 69023 ( LNER J72) originally had a vacuum ejector but the vacuum didn't apply the loco brakes, which were steam, as there was no form of combination valve. Did this apply to any other BR locos? 69023 has now been modified to have a BR standard combination brake valve so application of the train brake will apply the loco brake.