Permanent way terminology — what is the rail-joint arrangement called when the meeting ends of two rails are directly supported on a single sleeper?

Introduction / Context:
Rail joints are critical components of traditional (non-welded) railway track. They connect adjacent rail lengths and transfer wheel loads safely to the sleepers and ballast. Understanding joint nomenclature helps track engineers select the right detailing for load transfer and maintenance. This question asks you to identify the proper term for a joint where the rail ends are resting on, and thus directly supported by, one sleeper placed beneath the joint.

Given Data / Assumptions:

• Two adjacent rail ends meet at a joint.
• There is a single sleeper placed exactly under the joint.
• Standard fishplates and bolts are assumed, as in conventional jointed track.
• No special expansion device or welded arrangement is implied.

Concept / Approach:

Rail joints are classified by the position of the sleeper(s) relative to the rail ends. In a supported rail joint, the joint is directly over a sleeper, giving immediate vertical support to the wheel load right at the gap. In a suspended rail joint, the joint lies between two consecutive sleepers, so the rail ends are effectively 'suspended' between supports. Correct identification relies on recognizing where the sleeper is placed relative to the rail ends.

Step-by-Step Solution:

Verification / Alternative check (if short method exists):

A quick mnemonic used in permanent way practice: 'Supported has support under the joint; suspended has space under the joint.' If a wheel rolls across the joint and the sleeper is right below, it is supported. This aligns with the given condition, confirming the answer.

Why Other Options Are Wrong:

Suspended rail joint: The joint would lie mid-span between sleepers, not over one sleeper; this contradicts the problem statement.

Bridge rail joint: A special jointing arrangement (e.g., to connect unequal rail sections) using a bridging plate; not defined by the sleeper being directly under the joint.

Square rail joint: Refers to the joint being set normal (square) to the rail, unrelated to sleeper support position.

Common Pitfalls (misconceptions, mistakes):

Students often confuse 'supported' and 'suspended' because both use fishplates and bolts. Always check the sleeper location: under the joint equals supported; on either side equals suspended. Also, do not mix special-purpose terms like bridge joints with basic positional classifications.

Final Answer:

supported rail joint