In 1969 two power cars (51137/50) were adopted for use from Bristol Marsh Junction and Reading, working with GUV vehicles (W86174/W86572) sandwiched between them.
They were used on a night Airfreight Parcels service between Bristol and Hayes (for Heathrow Airport) and were also available for daytime express parcel Bristol - Birmingham runs when required.
"Railair Express Parcels" was the brand name of a new service introduced by the Western Region on the 6th October 1969 with a dual aim: to get a foothold in the airfreight market, which was at the time expanding by 20% annually; and indirectly, to promote the whole rail express parcels service. The train operated each way nightly between Bristol and Hayes (for Heathrow), with scheduled connections at Bristol for traffic to and from South Wales and the far west.
To operate the service the two power cars and two GUVs were converted at Newton Abbot. The GUVs were wired for DMU operation and had strengthened floors to accommodate consignments on pallets or in BRUTE trolleys. The power cars had their seats removed, and could take larger packages not suitable for bulking in BRUTES or for palletisation. They were in Rail Blue livery with 'Railair Express Parcels' on both sides of all four vehicles, and reclassified as Class 130s as were the earlier 1967 conversions.
Hayes, just three miles from Heathrow by road, had a fully-equipped parcels terminal which could handle not only this initial service comfortably but also additions if the idea developed into a network of services to and from provincial centres. Substantial growth would require a bigger site. BR's marketing hope was that agents would buy space on the train on a contract basis, the rates being pitched for competitive appeal to the many potential customers with insufficient traffic to make bulk for a road vehicle load. If the service made its hoped for impact, the WR's West of England executives saw the potential in time for a rake of 12 GUVs or even more each night.
In addition to Bristol, nine principal centres in the west and south Wales was linked with the Bristol - Hayes DMU by cross-platform exchange of goods at Bristol. For exports, the latest time of acceptance for each night's service ranged from 13:25 at Carmarthen and 15:00 at Plymouth to 20:00 at Bristol; on the return working each night, earliest collection times for imports ranged from 08:00 at Bristol to 10:50 at Plymouth and 12:50 at Carmarthen.
In April 1972 the vehicles were placed in store. 51150 was apparently later destroyed by fire, but both were withdrawn the week ending 21st Oct. '72. The two GUVs survived a bit longer as trailer vehicles for WR parcels units.
Details about preserved Class 116s can be found here.
Thanks to Mac Winfield, Ian Fleming and John Thomlinson for much of the information on this Class.