The following articles represent a collection of things I witnessed or came across – and you might find useful – when running a Feldbahn 0‑6‑0 or similar engine.
Howling Loco
A howling or humming sound like a low, sustained “houuuuugh” – can be louder than the steam whistle. This usually indicates a hole in the fire, where cold air is drawn through the grate, causing the boiler tubes to vibrate – absolutely undesirable, especially for rolled-in tubes! However, this is not always the case. Especially not with the SRS marine-type boiler. Even when the firebed is laid perfectly, the boiler tends to howl under load due to a shallow firebed – a consequence of the grate’s relatively high position – which doesn’t give the air enough time to heat fully....