WASHINGTON — After nearly 37 years in service, Amtrak will retire its last AEM-7 electric locomotive from passenger service on June 18 with a “Farewell excursion” from Washington’s Union Station to Philadelphia and back.

The AEM-7 locomotives have traveled more than 220 million miles since they first went into service in 1980.

Amtrak began replacing the AEM-7 fleet with a fleet of 70 advanced Siemens Cities Sprinter locomotives in February. Only three AEM-7 locomotives remain in service today.

The AEM-7 farewell will depart Union Station at 9:10 a.m. on June 18 for a nonstop run to Philadelphia. Passengers then will get off the train and go on a walking tour of the shop facility that has serviced locomotives dating back to the days of the Pennsylvania Railroad.

At 3:45 p.m., the AEM-7 train will return to Union Station for the final leg of its passenger revenue service.

Tickets for the farewell excursion went on sale Monday at $155 per adult, and half-fare for children. It includes lunch, a souvenir lapel pin and photo opportunities.