Scotch Marine Boiler — Shell Diameter Range For a Scotch marine boiler, the typical outside diameter of the cylindrical shell most commonly falls in which range?

Introduction / Context:
The Scotch marine boiler is a compact, fire-tube shell boiler widely used on ships and in stationary service. Knowledge of typical dimensions, such as shell diameter, helps in preliminary layout and comparison with space constraints.

Given Data / Assumptions:

• Standard single-ended Scotch marine boiler configurations.
• Normal pressure and capacity ranges as found in practice.

Concept / Approach:
Typical Scotch boilers use relatively large shells to accommodate multiple furnaces and fire tubes. The commonly cited shell diameter band for standard units is about 2.5 to 3.5 m, balancing heating surface, tube length, and furnace arrangement with shipboard space limits.

Step-by-Step Solution:
Recall standard catalog dimensions for marine boilers.Relate furnace and tube layout to shell size; practical ranges cluster near 3 m.Select the range 2.5–3.5 m as the most typical.

Verification / Alternative check:
Historic ship plans and boiler manuals list shell diameters frequently near 3 m, supporting this choice.

Why Other Options Are Wrong:
1.5–2 m: too small for most Scotch layouts with multiple furnaces.3.5–4.5 m: larger than common single-ended units; less typical for the referenced standard size range.none of these: unnecessary because 2.5–3.5 m is a recognized typical range.

Common Pitfalls:
Confusing overall boiler envelope with shell diameter; lagging and mountings add to overall size.

Final Answer:
2.5 to 3.5 m