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GWR Pannier Tank (LBSC 'Pansy')
by Barry Leach
Barry Leach

Back in the early 1980's I completed my first steam locomotive - a 5"Gauge GWR Pannier Tank - to the LBSC Design 'Pansy'. I've regularly steamed the locomotive for the past 15 years and can honestly say that it has been one of the most reliable steam locomotives with which I've been involved. For the most part LBSC's design is very sound, the locomotive is a very good steamer and has been an excellent passenger hauler during the society 'open' afternoons. Stage 1

For any prospective builder I would heartily recommend it as a good steam locomotive. However, there are a few pitfalls one should be aware of:

  • The slide valves are driven by a rocker shaft directly from the die-block. It is advisable to fit additional bearings to the motion plate to provide support for the rocker shafts on either side of the slide valve drive arms. Without this bearing the load on the slide valves will cause the single centre bearings to wear into a 'barrel' shape within the first twelve months of use.
Stage 2
  • Protection around the rear axle and axleboxes is essential. Much coal dust from the footplate drops through and onto the axle/axleboxes. Keeping this dust from these bearings will greatly improve their life.
  • Be careful with the purchase of the casting for the 'Inner Dome Bush'. In its unmachined state my casting was short of the required length by about 0.125". Suppliers can be reluctant to acknowledge these types of problem - it's not their responsibility(?).
  • My drawings show the blast pipe centre line and the chimney centre line in different positions. They should be the same.
  • The dimensions for the cabside doorway do not match the drawing. Check them out.
  • Beware of using OLD drawings. My original drawings for Pansy, purchased in the late 1960's, have the boiler dimensioned incorrectly. It will not reach the smokebox, being short by about 0.187". The boiler barrel length should be 11.625" and the outer/inner firebox length should be 5.5/4.625, respectively. Check your drawings.
  • I consider the positioning of the emergency handpump in one of the sidetanks to be questionable. Use of the handpump puts much stress into the supporting platework and whether one could safely use the handpump whilst on the move is suspect. Fitting the handpump crossways into the bunker space, directly to the buffer beam, gives a very firm position with easy access when running.
  • Give much consideration to the lubrication of all the 'between frames' motion. Wear on this motion needs to be kept to a minimum as much as possible. Whilst being an excellent 'runner', when maintenance of the motion is required a major stripdown is required.
  • The boiler works extremely well with the softer Welsh steam coals. However, when using the harder 'Anthracite' type of coal it is extremely difficult to get the coal to burn completely away. It leaves small glowing embers which after about an hours running fill the firebox, making it difficult to maintain pressure. At this point the grate has to be dropped and a new fire lit for another hours run. Perhaps someone might have an answer to this!

Complete 1985


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