Gatwick Airport (GTW) to Southend Airport (SIA) train with Abellio Greater Anglia

Greater Anglia is a train company based in the United Kingdom. It operates a wide range of services, from commuter trains to intercity services. The commuter trains run at regular intervals throughout the day, while the intercity services run at peak times. The train types include the InterCity 125, InterCity 225, Class 90, Class 91, Class 360 and Class 379. The ticket types available are Standard, First Class and Advance. The most popular routes for Greater Anglia are London Liverpool Street to Norwich, London Liverpool Street to Cambridge and London Liverpool Street to Ipswich.

Southern Rail is a train company based in the United Kingdom. It operates a wide range of services, from high-speed intercity trains to local commuter services. Its trains include the InterCity 125, InterCity 225, and Class 444 and 450. It also offers a variety of ticket types, such as Advance, Off-Peak, and Super Off-Peak. The most popular routes for Southern Rail are London to Brighton, London to Southampton, and London to Portsmouth.

Thameslink is a train service that operates in the United Kingdom. It is operated by Govia Thameslink Railway and serves the counties of Bedfordshire, Cambridgeshire, Hertfordshire, London, and Surrey. The trains run from early morning until late at night, with some services running 24 hours a day. There are a variety of train types available, including Class 700 Desiro City, Class 377 Electrostar, Class 387/1 Electrostar, and Class 319/0. Ticket types include Anytime, Off-Peak, Super Off-Peak, and Advance. The most popular routes for Thameslink are London to Brighton, London to Bedford, and London to Luton.