Most of this profile is based on text kindly provided by William Snook.

Just a single batch of 50 PILCHARDs was built by Butterley Engineering for BR between May 1950 and May 1951 ^[1]. The wagons were built under diagram 1/571 to lot 2121 and were later assigned TOPS code YCO-A and design code YC500A. They were numbered in the departmental series as DB990050 to DB990099, following on from the GUDGEON wagons that were also built by Butterley but which were a very different type.

The 20-ton PILCHARD was a peculiar bogie ballast and sleeper wagon, similar in principle to the DOLPHIN and STURGEON wagons, with small wheeled (2ft 6in diameter) diamond-frame bogies and dropside doors (3 per side) to ease handling of heavy track components. In fact, the PILCHARD could be seen as a mini-STURGEON, with both the length and carrying capacity being roughly half that of the larger design.

The origin of the design appears similar to LNER and their predecessors. LNER diagram 204 was issued for this type ^[1], but so far as can be ascertained none were actually built before Nationalisation. PILCHARDs were allocated exclusively to the ER/NER ^[1] but, being unfitted, they went out of use during the early 1980s.

Engineer's ballast trains were marshalled at the request of the department concerned to accommodate the work. PILCHARDs were unfitted so every train conveying them on a running line would have to have a brake van at the rear. In fact unfitted ballast trains were the norm until the 1970s. Often there would be a mixture of wagons so that empty wagons (e.g. open service) for removing spent ballast from site, Ballast and Sleeper wagons loaded with track components for relaying, ballast opens or hoppers with new stone, and very often a permanent way crane would all be found in the formation. It is highly unlikely that a block load of PILCHARD wagons would be put together.

Most District Engineers had a permanent allocation of dedicated wagons and had to use them carefully so that they had enough wagons for the planned work. Meetings were held a few weeks before the job where the requirements were discussed and agreed, and the train planning clerk would be given the specification so that the special traffic notice (STN) would be correct. An STN was issued every week, which listed the ballast trains to run to the various worksites. The notice included the train formations, especially the order of the wagons to arrive on site to facilitate the work.

PILCHARDs were useful in carrying medium sized components, especially parts of points and crossings which required longer point timbers and switches and crossings to relay junctions. Other wagons such as DOLPHINs, SALMONs and STURGEONs being 60 foot or more in length would be more useful for plain line rails and sleepers, including pre-fabricated panels.

Perhaps the most common type of Ballast and sleeper wagon was the GRAMPUS, which BR built in massive numbers. These were not always long enough for relaying material for junctions, which is why the PILCHARD survived as long as it did.