The original K&L track had thick sleepers. It was when Alan Gibson became involved in the sale that thim sleepers were produced to match existing OO track. Thick sleepers were also produced. Allof the track work I have done has used thick sleepers. The track o Hawes was started in the mid 90s and despite being kept in a variety of conditions is not a problem. It has been painted. Some of the chairs from 1 batch were very brittle but these were produced when the moulding was outsourced.