Receiver-Type Compound Steam Engine — Cylinder/Crank Arrangement In a receiver-type compound steam engine, how are the high-pressure (HP) and low-pressure (LP) cylinders arranged mechanically for typical smooth running?

Introduction / Context:
Compound steam engines expand steam in two stages: first in a high-pressure (HP) cylinder and then in a low-pressure (LP) cylinder. A common mechanical layout is the receiver-type compound engine, widely used to improve torque uniformity and efficiency. Understanding its mechanical arrangement is essential for recognizing indicator diagrams, valve timing, and performance behavior.

Given Data / Assumptions:

• Two cylinders (HP and LP) connected through a receiver volume.
• Conventional marine and stationary practice for smooth torque.
• Goal: identify the typical crank/cylinder arrangement.

Concept / Approach:
In a receiver-type compound engine, the HP exhaust passes into an intermediate vessel called the receiver before admission to the LP cylinder. To avoid dead-center problems and to smooth the turning moment, the HP and LP cranks are usually set about 90° apart. Each cylinder has its own piston rod and separate crank. This phase difference allows one cylinder to produce torque when the other is near dead center and gives time for steam transfer into the receiver.

Step-by-Step Solution:
Identify receiver function: buffer the HP exhaust before LP admission.Note mechanical layout: HP and LP have separate piston rods and separate cranks.Set crank phasing: approximately 90° for uniform torque and proper receiver filling.Conclude: the receiver-type uses separate cranks at about 90° with a receiver.

Verification / Alternative check:
Historical engine drawings and standard texts show two cranks at right angles with a clearly labeled receiver between cylinders.

Why Other Options Are Wrong:
Common piston rod (tandem): that is the tandem type, not the receiver type.Common rod without receiver (Woolf): that is Woolf’s type; again, not receiver type.V-arranged on one crankpin: not the conventional compound receiver layout.

Common Pitfalls:
Assuming “compound” always means tandem; receiver-type uses separate cranks and a receiver volume.

Final Answer:
Separate cranks set approximately 90° apart with a receiver between cylinders