The Grand Liner (連結合体 グランドライナー) is GoGoFive's second and largest mecha — and the very first train-themed mecha in all of Super Sentai history. It is formed from five heavily armored trains, GoLiner 1 through 5, which roll out of the team's Bay Area 55 base and couple together into a towering robot on the command "Renketsu Gattai!" (連結合体, "Linked/Coupling Fusion"). In Power Rangers Lightspeed Rescue this same machine is known as the Supertrain Megazord.

Each of the five GoLiners is its own type of train — a steam locomotive, an electric tram, an armored military train, a subway car and a Shinkansen bullet train — and each becomes a body section: GoLiner 1 the left arm, GoLiner 2 the right arm, GoLiner 3 the torso, and GoLiner 4 and 5 the legs. In coupled train mode the GoLiners double as transports, their cargo bays carrying Victory Robo's rescue vehicles to the scene of battle.

Standing at least 1.4 times taller, the Grand Liner is noticeably bigger and stronger than Victory Robo. Its right shoulder mounts the Liner Gatling and its left the Liner Homing, which fires either explosive or freezing missiles — powerful enough to extinguish an erupting volcano — with the Grand Storm as its finishing attack. The trade-off for all that mass is speed: against faster, more nimble Psyma Beasts the team still has to fall back on the more agile Victory Robo. (Not to be confused with the separate Max Liner / Liner Boy, which combines with Victory Robo to form Max Victory Robo.)

As a toy, the Grand Liner arrived in 1999 as one of the largest DX sets of its era — released by Bandai Japan as "連結合体 DX グランドライナー" and by Bandai America as the DX Supertrain Megazord for Lightspeed Rescue. All five trains first couple into a long convoy and then build up into the imposing combined robot, complete with spring-loaded missile launchers and storage bays for the Victory Robo vehicles. In 2020 Bandai revisited the design as a "Super Mini-Pla" model kit — a roughly 27 cm build that collectors regard as one of the most ambitious projects in the whole line.