MEC 343 & B&M 342 haul POWA through Royal Junction on April 8th of 2005. Video by John Erickson.
MEC 347, 377, 517, & 379, & ST 621 pull out of the siding at New Glouster with POWA on April 11th of 2005. Video by John Erickson.
MEC 514 & MEC 321 power POWA up the hill at Read St in Portland on November 5th of 2009. Video by John Erickson.
MEC 517, HLCX 6404, HLCX 7182, & MEC 608 power POWA through Gray on May 6th of 2010. Video by John Erickson.
MEC 514, GMTX 3003, and BM 335 take POWA through Libby on August 9th of 2014. Video by John Erickson.
It's a mixed bag of power on POWA today, MEC 518, NS 3470, MEC 321, & GMTX 3001 as they come across the Androscoggin River bridge into Lewiston on August 28th of 2014. Video By John Erickson.
MEC 519 leads 518, 503 and 343 with POWA through Green on July 22nd of 2015. Video by John Erickson.
MEC 306 leads GMTX 3005, 345 and 518 with POWA through Green on July 26nd of 2016. Video by John Erickson.
MEC 312, 505 & 377 arrive with POWA at Strawberry Ave on September 20th of 2016. Video by John Erickson.
MEC engines 600 3404 and 604 take POWA through Green on December 30th of 2017. Video by John Erickson.
MEC engines 600 3404 and 604 with POWA meet WAPO with MEC 327 and 7605 at Leeds Junction on December 30th of 2017. Video by John Erickson.
PanAm MEC engines 7585, & 3405 bring POWA through Monmouth on November 7th of 2020. Video by John Erickson.
PanAm MEC engines 7585, 7518, 506, 7534, & 619 bring POWA through Oakland on December 4th of 2020. Video by John Erickson.
Symbols
PanAm used a four character symbol to refer to each train that could tell you where the train started from and where it ended up. Long distance trains got four letters, the first two for the origin, and the last two for the destination. Switchers got two letters a dash and a number. The nicknames used could confuse this though (Sappi-3 was actually SP-3, I believe). The OCS (Officer and Crew Special) was a passenger train used to reward employees for good service and give dispatchers, company officers, and prospective customers a look at the lines. It usually consisted of three former parlor service cars pulled by two FP9 locomotives built in 1954. And the Oil Extra was a train that ran as a stop-gap measure during the Lac-Mégantic accident and Montreal, Maine and Atlantic Railway bankruptcy and sale to the Central Maine and Quebec Railway.
I will list the symbols I know with their end point city or town.