The Southern Railway was the only mainline railway to embrace electrification wholeheartedly, creating what was at the time the world’s largest electric suburban network. It was the only railway to use passenger train ferries allowing its night sleeper service between London and Paris to operate as a true through service. Its "Golden Arrow" all-Pullman day express even had its own luxury channel ferry. These achievements would have been noteworthy at any time, but were set against the background of worldwide depression. is that of a remarkable railway which was dependent on passenger traffic rather than freight. It was a commuter railway, an international express railway, and a holiday railway serving many of the most popular seaside resorts.