The photo would appear to be of a modern railway locomotive, regularly used to haul express passenger train, actually the Cornish Riviera sleeper train to Penzance from London's Paddington station.
The locomotive in question through was actually built in the early 1960s, one of the ubiquitous Class 47s, and would have been hauling express trains on Britain's railways while steam locomotives where still a common sight.
What has allowed this iconic locomotive to stay in front line revenue earning service for many years yet? Put simply, a retrofit solution.
The original Sulzer diesel, a large 16 cylinder medium speed 4 stroke diesel, very much of 1960s technology, was removed and replaced with a modern North American built 2 stroke V12 engine coupled to a robust and reliable alternator rather than the original DC generator and the auxiliary systems renewed.
The result, a modern, efficient and powerful locomotive capable of a wide variety of duties for a third of the cost of a new locomotive.
Retrofit IO systems share the same philosophy, pre-existing and robust panel systems and their field wiring are analogous to the body shell and running gear of the original Class 47, which with care, has an almost indefinite life, and can be quickly and easily up graded to a modern and powerful BMS using a retrofit solution, speeding the process and reducing the cost in line with what an organisation can afford.
So just as rail operators have been able to improve performance and reliability and reduce their operating costs, building operators can equip themselves with a modern and reliable BMS for substantially less than they would have been expecting to pay via the old fashioned route of a complete strip-out and starting again.