Locomotives

CLASS 25/3

Heljan have announced a much needed re-run of this ever popular loco which should become available in the first half of 2026. All versions are being produced fully numbered with a total of six liveries being produced. As well as the standard BR green and BR blue liveries several of the more unusual celebrity machines are being produced.

Heljan have released the colour layout images for these which are shown on this pages but we have also left some of the images here from the previous production run as well but note all six models being produced are factory numbered already.

As always we are also offering our weathering service for an additional £50.00 with the customer's choice for the degree of weathering. The loco has been updated with the improved wheel pattern, as per the Class 24, with drilled holes but has not been updated with "plug-and-play" facility sadly There is also the option of sound fitting as well through the workshops at an additional £330.00 using the ESU v5.0 XL chip.

LOCOMOTIVE SPECIFICATION.

The final batch of Class 25 locomotives were designated Class 25/3 and was to be built by BR Derby and Beyer, Peacock and Company of Manchester. However, because of financial problems Beyer, Peacock was unable to complete the final 18 locomotives and these were transferred to BR Derby for construction.

Though these locomotives still carried a RTB 15656 generator, this variant was a ten pole machine with a modified assembly incompatible with earlier equipment. The regulated (full hp) part of its characteristic was substantially the same as before but the unloading point, that is the point at which full power could no longer be utilised, was altered to 900 A, 910 V (819kW) from 1,050 A, 780 V (819kW). Only two stages of field weakening were employed, previous machines had six, and this provided ‘full power’ at speeds between 7 and 80mph (130 km/h), and maximum tractive effort was reduced to 41,500 lbf (185,000N).

The latter half of the 1960s had seen the widespread introduction of solid state electronics and these locomotives incorporated a control system where speed was detected electronically rather than mechanically. A signal from a tachogenerator was used to close contactors in sequence at given speeds to activate the motor's field weakening process, rather than through contacts and relays as in earlier types. The control system ensured the traction motors and main generator were all operated within the continuous rating of the machines except in full field conditions when the driver was able to judge how long to remain in the short-term rating condition. There were two variants of the Class 25/3 sub-class. Early 25/3 AV locomotives were fitted with vacuum brakes and in due course many of these were dual braked and redesignated 25/3 BX. By the time the last few locomotives were under construction dual braking had become the norm and ten of the last batch from Derby were built new as 25/3 BX locomotives for work out of Willesden on the recently upgraded West Coast Main Line.