The following photo was posted on the Electric Railroaders page. There was some discussion as to the timing and circumstances of the photo. The initial thought was that it was some sort of fan trip. However after more study, it appears the photo likely dates to the opening of BRT service on the Williamsburg Bridge in 1908. At this time, the line switched off of the Broadway El in Brooklyn to access the bridge and the tracks went across the bridge to an underground terminal at Essex Street and Delancey street in Manhattan. Shortly thereafter, the BRT tracks were extended west and south in Manhattan to the Bowery , Canal Street and Chambers street stations. BRT and the LIRR had joint operations on this line so this was the LIRR's initial terminal in Manhattan, two years prior to Pennsylvania station. The cars that were used on the BRT and LIRR were wood sided El type cars as we see in the photo. The LIRR probably did operate mp-41s on this route although i have not come across a photo yet.
The trolley in the picture to the right is a Metropolitan Street Railways car, perhaps a Grand street or 4th ave car . It was on its way to Washington Plaza on the Brooklyn side where the company had a large trolley terminal. This company operated street cars on the North side of the Bridge until 1932. Metropolitan Street Railways was acquired by New York Omnibus corporation which subsequently became Fifth Avenue Coach company. I do not believe that this company ever operated busses on the Williamsburg Bridge after 1932. The Tracks of the B&QT trolleys were to the left of the view in the picture. These cars accesed an underground terminal in Manhattan went across the Bridge and served various routes in Brooklyn and Queens.
El cars used by the BRT at the time were Woodsided gate cars . These operated on the Bridge line down to Chambers street via the subway at the time. The BRTs first steel car was the Standards and these did not arrive until 1916. Note in the photo, that the third rail was not covered as they are today.
Enjoy the Photo. It is the earliest photo I have seen of BRT operations on the Williamsburg Bridge. It is also a rare photo of a Metropolitan street Railway car on the bridge as well.