I suspect it’s suiting fabric from the North. This happened on the SLNC. A crew was given such a bale to get across into Eire and hid it in the coal bunker. Someone at Enniskillen saw them do it, and gave Eire Customs a tip off - the white capped inspectors moved purposefully towards the loco at the Glenfarne customs stop. The crew quickly disposed of the hundreds of pounds worth of material in the firebox…