During the time a few years ago when 19 was out of service in the height of fire season, we pulled our usual 5 car consist along with 2 WP&Y flats as idler flats and the former UTLX tank car. As Jim who has more time on #3 than probably anyone else says, normally the injectors have to be worked intermitantly. When we were pulling the above heavy consist I found that above the highwy where the grade steepens a bit, I pretty much ran the fireman's injector steady on the lowest setting of the water valve which is about 3/8 turn open till we got to the upper end of the S Wye area, where I turned it off and traded water for steam to the depot stop. It was quite challenging to keep up.