General Motors has a long & storied (and sometimes convoluted) history of involvement with railroading. Most know that Electro-Motive became a Division of General Motors, and thousands of locomotives & engines were built under the GM banner.

One early strong connection to General Motors was instrumental in the development of an important safety system on trains, which was the standard for that system for decades upon decades. Name the person and the system involved.

I'm looking right at you, DD.....

Harold Hamilton the father of diesel locomotives?

George Westinghouse and air brakes? Westinghouse bought Frigidare from GM, so that's at least a tenuous connection between the two.

my first thought too was the airbrake (being less than 3 miles from the original Westinghouse works)

Interesting direction there.... can you connect it to an early major figure in GM history ?

No, I don't really see a connection.

How early and important of a figure are we talking? I don't think Durant or Mott had anything to do with trains, and the only train connection I can think of with regards to Sloan is the street car scandal. What are we missing?

You're missing the correct guy.

Yep, he's early and he's significant.

I'll say Kettering and the electric starter, since there haven't been any deaths from people trying to pull start their diesel locomotives after that was invented.

Circa 1884, the Westinghouse Air Brake Company was experimenting & developing the railroad air brake. Though the new concept was correct, the early execution was far from perfect. Crude manufacturing resulted in the high pressure air leaking out, causing poor stopping power/distances. Westinghouse crews spend some degree of time altering & tweaking the air brake units, and re-installing them on test RR cars, only to find repeated unsatisfactory performance.

A traveling salesman, a representative for a tool & machine manufacturer, stopped at Westinghouse and became involved as an observer to these tests. After some discussions on machining with Westinghouse engineers, said salesman met with the skeptical superintendent, and convinced him to allow the salesman a small quantity of rough castings to take back to his firm. On an improvised machine, the salesman (also learned in the machinist's trade), finished a complete set of parts by precision grinding them to close tolerances.

Returning to Westinghouse, the salesman observed said parts in their first trial test. They performed with excellence, and the salesman accepted a quantity order for grinding machines. The salesman expected the machines might not be well understood in their operation, and offered to send along some mechanics for instruction. Westinghouse declined, with the result that after a few months, the machines were judged to be useless.

The salesman returned himself, gave demonstration & instruction, and within a few days all machines were successfully operational and producing consistent, quality products.

The lesson proved was that parts accurately made could hold air under high pressure, and the air brake became a long-standing railroad industry standard.

The salesman/machinist worked for the Brown & Sharpe Manufacturing Company of Providence RI, and went by the given name of Henry Martyn Leland, future founder of Cadillac.