The two engines, hard-wired to act as one, not just provide additional power to the train but also reduce the acceleration and deceleration times of the train significantly, making higher averages speed possible.

Train -18, the first of the new Rajdhanis that will be flagged off by Prime Minister Narendra Modi on February 15, has quietly crossed a milestone for another kind of train technology that will allow Indian Railways to achieve higher speeds for our Rajdhani trains and reduce travel time without increasing expenses.

A "push-pull" technology, in which there is a front engine pulling coaches and a rear engine pulling the rear, was used on the Mumbai Rajdhani via Central Railway route Wednesday.The technology received a safety clearance from the Commissioner of Railways on Wednesday morning, as well as a speed certificate from the Research Design and Standards Organization, following successful trials last week.The speed certificate issued for Rajdhani Express route across Central Railway from Delhi to Mumbai is 130 kmph.Among the NDA government's highlights on the speed upgrade project of Indian Railways, this will be its next showcase.

.Sources said Railways plans to deploy these trains as Rajdhanis.The locomotives are pulling Rajdhani-type Linke Hoffman Busch coaches.With existing coaches and engines, we can achieve much higher average speeds and reduce travel times," a senior Railway ministry official said.

Unlike the distributed power technology, which is not powered by a locomotive, the push-pull technology relies on two locomotives that are powered by their haulage power.There are several railways abroad using this technology for long-distance fast services, including France's TGV, the US's Acela, the KTX in South Korea, and the Spanish Talgo.

The RDSO stipulates when issuing speed certificates that the rear engine must always push less than the front engine.According to this rule, the rear engine is to be the "slave" of the front engine.The engines are wired with a sophisticated technology to act like one, but the standards group stipulations aim to prevent any safety risks.Indian Express reports extensive and successful testing has taken place.

As the new technology has been approved to run only at the speed that its tracks are capable of supporting, quicker acceleration and deceleration saves time during numerous speed restrictions, curves, and stoppages, which in turn adds up to a faster journey.