Scotch Marine Boiler — Furnaces in a Single-Ended Unit A single-ended Scotch marine fire-tube boiler may be fitted with one to four furnaces entering from the front (uptake) end of the boiler shell. Evaluate the statement.

Introduction / Context:
The Scotch marine boiler is a compact fire-tube design historically used in ships. Understanding the number and placement of furnaces helps identify the design and capacity range of single-ended units compared with double-ended variants.

Given Data / Assumptions:

• Single-ended Scotch boiler (furnaces at one end only).
• Multiple furnace tubes may feed a common combustion chamber.
• Application in marine service with forced/natural draught arrangements.

Concept / Approach:
Single-ended Scotch boilers commonly employ one, two, three, or four furnaces entering from the front end. The furnaces discharge into a common combustion chamber before hot gases pass through numerous small fire-tubes back to the smoke box, enabling large heating surface in a short length.

Step-by-Step Solution:
Identify boiler type: single-ended ⇒ all furnaces are on the same endplate.Capacity scaling: more furnaces allow higher firing rates and greater heating surface.Hence, “one to four furnaces entering from the front end” is consistent with established practice.

Verification / Alternative check:
Marine engineering texts describe 1–4 furnace single-ended boilers and 2–8 furnace double-ended versions (furnaces at both ends), confirming the statement for single-ended units.

Why Other Options Are Wrong:

• Incorrect: Conflicts with standard Scotch boiler configurations.
• Superheat/double-ended qualifiers: Unrelated to the single-ended furnace count.

Common Pitfalls:
Confusing the number of furnaces (large tubes) with the number of small fire-tubes; they serve different roles.

Final Answer:
Correct