Very few of the "first generation" diesel multiple-units have survived in service into the privatised era. Those which have are generally called "heritage" units, presumably because this sounds rather better than the possible alternative names. Here is one such, a class 117 unit, photographed in Regional Railways livery with Scotrail insignia, at Edinburgh Waverley on 26 September 1997. 

The service between Leeds and York via Harrogate has been operated in the late 1990's by diesel multiple units of classes 141, 142 and 144. Here is unit 142 074 standing at York on 4 October 1997, preparing to work back to Leeds.

Two-car class 142 unit 142 025 carries a non-standard brown, beige and white livery as evidence of a period spent in the West Country. Subsequently re-allocated to the North East, it was photographed at Leeds on 31 July 1998.

Class 143 2-car set 143 605, photographed at Cardiff Queen Street on 6 April 1998, is in the livery of Regional Railways, including Regional Railways branding on the side of the coaches.

Class 144 two-car unit 144 001, standing in a bay platform at York on 4 October 1997, is in the maroon and cream "Metro Train" livery of the West Yorkshire Passenger Transport Executive. It also carries "Regional Railways" branding.

A plaque near the station entrance remarks that York station is one of the finest buildings of the Victorian age. I'll second that.

The higher-numbered class 144 units are three-car sets, and in 1998 these have been the usual stock on the Leeds to York via Harrogate services - which to my mind is excellent, because the large windows are ideal for surveying the pleasant scenery on the route. In this photograph, taken from Knaresborough Castle, one of the units is seen crossing the River Nidd viaduct on 1 August 1998.

Centro - the operators of trains in Birmingham and the West Midlands - have adopted this green, white, blue and grey livery which includes the Centro logo (the yellow rectangles near the doors). Here, a class 150 unit stands at Birmingham New Street on 27 April 1998.

In the Regional Rail colors of the time, ex works 150266 passes Stenson Junction in July 1996 heading towards the Birmingham area.

Photograph by David Cable

A class 150/2 set enters Pontypridd with a southbound service on 15 February 1997. The livery is again that of Regional Railways, although in this case, there is no "REGIONAL RAILWAYS" lettering on the coach.

Pontypridd is a large station, with many platforms, a good number of which are no longer in use. Just ahead of the train is Taff Vale Railway milepost 13.

The single-car units of class 153 began life as two-car units in class 155! Most of the class 155 sets were broken up in this way, with each coach being modified by the addition of a cab to what had been the inner end. Here, unit 153 377 stands at Salisbury on 6 April 1998 while working a Salisbury to Bristol service. It is in the livery of Regional Railways, and the end nearer the camera in this picture is the original cab.

153 371, photographed at Wolverhampton on 13 June 1998 is seen from the opposite end to 153 377 above. This shows the Central Trains branding on this unit more clearly. The cab in the foreground in this picture is the one added during rebuilding, and it is possible to see in comparison with the preceding picture how much smaller this cab is. The other immediately noticeable difference is the location of the headlights.

As indicated above, not all of the class 155 units were rebuilt as class 153. Those operated by West Yorkshire PTE have continued in their original formations, and, like 155 346 - seen here at York on 2 August 1998 - have acquired the maroon and cream West Yorkshire Metro Train livery.

The Regional Railways Express livery has been applied to a number of class 156 units, though the result arguably has less aesthetic appeal than on the class 158 sets. Here, unit 156 416 awaits departure from Crewe with a Nottingham service on 27 April 1998. Central Trains branding has also been applied to this unit.

Some of the class 156 units operated by Regional Railways North West have been given a version of the Regional Railways livery with a slight variation - the pale blue bodyside stripe has been replaced by a green one.

Here, unit 156 441 exhibits this livery variety (not to mention a very bright front-end catching the sun!) at Manchester Piccadilly on 27 April 1998.

Still in its original livery, including "Super Sprinter" branding, unit 156 473 stands at York on 2 August 1998. The yellow rectangle containing the black cross on the left-hand windscreen is an indication that other units should not be connected in multiple with this one.

Unit 158 780, photographed at Gloucester on 11 April 1998, is in Regional Railways Express livery, but has the addition of white "Central Trains" panels on each coach.

Unit 158 837, photographed at Bath Spa on 9 April 1998, is also in Regional Railways Express livery, but this time, there is the addition of blue Wales & West Railway "Alphaline" panels on each coach.

Increasingly, these units are also receiving Wales & West Branding including the new W&W logo within the dark blue bodyside stripe. (The example shown here was on unit 158 863, photographed on 28 April 1998.)

Ten class 158 2-car sets have been leased by West Yorkshire PTE for their longer-distance services, and these all appropriately carry the maroon and cream WYPTE livery. Here, unit 158 906 operating a service from West Yorkshire enters Manchester Piccadilly on 27 April 1998.

Some of the class 158 units used on Trans-Pennine Express services are being repainted in the purple and metallic gold "Northern Spirit" livery. Here three-car set 158 811 leaves Leeds with a westbound service on 31 July 1998.

The three-car class 166 units are operated by Thames Trains, mainly on longer-distance services. Here unit 166 214 arrives at Ealing Broadway while working a London Paddington to Newbury semi-fast service on 21 December 1998. Although Thames Trains have adopted a blue and green colour scheme - evident on the bilingual station sign at Southall below - repainting their trains is not a high priority, and by the date this photo was taken, virtually all of them were still in their original Network SouthEast livery.