The seaside railway will operate four carriages together for the first occasion in four decades.

This weekend, the expanded timetable runs concurrently with the historic vehicle event linking the capital to the coast.

The increased frequency hopes to draw fans of classic transport while cutting passenger delays.

The volunteer group supporting the line will supply extra operators and control staff to supplement the permanent team.

Special procedures mean the carriages will cross paths at each siding point, rather than solely at the central stop.