HORNBY DUBLO COUPLINGS
Thanks to Club Member No. 4 - David SMITH for the answer
Hornby Dublo started fitting plastic couplings to locos and rolling stock from the middle of 1960. These plastic couplings (called FPC – First Plastic Couplings in reference books) allowed two 2-rail locos to run cab-to-cab or smokebox-to-smokebox without short-circuiting. Metal couplings had prevented this feature. Dublo received feedback pointing out that these plastic couplings were larger and more noticeable than the earlier metal couplings. As a result, Dublo developed a thinner, less intrusive coupling. This was introduced in early 1963 and is classified as NPC (New Plastic Coupling) in reference books. Because of large stocks of unsold items, there must have been large quantities of unused NPC lying in Dublo assets.
When Wrenn re-introduced the Dublo locos and wagons, Dublo couplings were supplied to allow compatibility with Dublo locos and wagons. These couplings were modified by having the tail and part of the boss removed (clipped) to allow “push fit” onto rivets on locos and wagons. Early (Period One) locos and wagons are found with NPC couplings as follows
W2218 two x NPC cranked clipped
W2221 one x NPC straight with clipped to allow it be pushed onto the rivet on the tender
W2224 one x NPC cranked clipped allow it to be pushed onto the rivet on front bogie plus one x NPC straight clipped to allow it be pushed onto the rivet on the tender
W2206 one x NPC straight clipped to allow it be pushed onto the rivet on the front plus one x NPC cranked with tail, which was held in place by a screw at rear. The cranked coupling also came with a seating washer and a rubber spring fitted over the tail.
Wagons came with two x straight NPC clipped to allow push fit onto brass rivets. The only exception was the Presflo chassis (W4626P and W4627P), which came with a rivet at one end and a screw at the blind hole below the representation of compressed air cylinders (as Dublo had done) To stop excessive movement of the couplings, the wagon chassis (except for the Presflo chassis) were modified by having a stop moulded onto the coupling location. The rivets and stops were removed during Period Two, except for the brake van chassis, which was never fitted with rivets and retained the stops until the factory closed. After a year or so, the couplings were no longer supplied with wagons, resulting in the “send 1/6d plus an s.a.e.” label, which is found on late Period One boxes
At some stage, supplies of couplings acquired from Dublo assets were exhausted and Wrenn had to start manufacturing their own stocks. The couplings manufactured were straight FPC and the cranked NPC. From Period Three, these unmodified couplings were supplied in loco boxes with attaching screws and collars as appropriate. Also, during Period Three, a coupling conversion set, W7304, was introduced. This contained four x straight FPC plus screws and collars to convert two wagons or coaches.
Couplings were omitted from Limited Edition loco boxes (1985) and from all loco boxes from around 1988 or 1989.