🔍 Key Concepts

• Boiler expansion and contraction and how drums are supported on a ship • Difference between fixed (rigid) supports and sliding/expansion supports • What the illustration labels (1–6, A–J) show about what is actually being supported and how it is attached to the hull

💭 Think About

• Look closely at which drum in the sketch is resting in the saddle and how the saddle is attached to the structure beneath it • Decide whether the arrangement shown would permit thermal expansion of the drum or hold it firmly in one place • Ask yourself whether any rubber or shock‑absorbing material is actually drawn in this figure, and where the movement (if any) would occur

✅ Before You Answer

• Verify whether the saddle in the upper view is under the steam drum or water drum • Check if the bolts go through the saddle into the base, or if there is a surface that would allow sliding/expansion between parts • Confirm if the lower close‑up view shows a fixed chock/bolted connection or a sliding foot with a low‑friction surface for expansion