and triple-car operations for T2-T3 services on PMS/North. Exterior-wise, the Crystal Mover vehicles are painted in a base livery of silver and grey, blending in with the color scheme of the airport terminal buildings. However, many units are decorated with colorful promotional liveries. Trains come in two interior color schemes: blue for PMS/North trains, and orange for PMS/South trains. All Crystal Mover vehicles have four wide-opening doors, two on each side. The interior features longitudinal seating at both ends of the car for a total of 8 seats, with a spacious standing area in the middle of the car for baggage and trolleys. At the ends of every car, an equipment housing offers a flat platform for additional seating. Trains were also fitted with two LED text displays located near the ceiling which display travel information, and two media screens displaying Airport promotional material. Train formation The configuration of a Crystal Mover in revenue service is just the one car. With both the motors and the third rail current collectors, the train cars can be coupled up to 2 or 3 cars during service. Signalling and operations In the Changi Airport Skytrain, the signaling system and the automatic operation system utilise a train detection system based on the check-in/check-out principle, an ATC and an overrun protection system (ORP) by on-board ATP. When a train enters the ORP signal aspect section, the on-board ATP device creates the ORP control pattern in a manner which protects the fixed-point stop control pattern by the on-board ATO. If the train speed overshoots the ORP control pattern, the emergency brake is activated, safely bringing the train to an emergency stop. The system also uses a by-pass operation between Terminals 2 and 3, where trains are placed under synchronous control so that they depart and arrive at each corresponding station at the same time. Specifically, the station departing times are synchronized by the count of the station dwell time which is automatically adjusted based on the stoppage state at the station. Also, the train speed is adjusted by ATO which recognizes signals which are sent from the way-side control devices to the on-board control device at the time of departure from a station so that the crossing times in the bypass section are optimized and their arrival times are synchronized. Redevelopment works In 2015, one portion of the Changi Airport Skytrain system connecting Station B and