trestlework

Nearer and higher loomed the steel trestlework upon which rested the giant engine.
The Man Who Rocked the Earth|Arthur Train
The trestlework is burned in places and across these we passed the best we could.
Diary of an Enlisted Man|Lawrence Van Alstyne
In 1868 the remaining trestlework was replaced with Bollman trusses.
Smithsonian Institution - United States National Museum - Bulletin 240|Anonymous
Men are busy rebuilding the burned out places in the trestlework and bridging the river, which is narrow here.
Diary of an Enlisted Man|Lawrence Van Alstyne

How he ever did it I don't see, but he said two soldiers fell through the trestlework and were hurt and had to be left behind.
Diary of an Enlisted Man|Lawrence Van Alstyne

British Dictionary definitions for trestlework

trestlework

/ (ˈtrɛsəlˌwɜːk) /

noun

an arrangement of trestles, esp one that supports or makes a bridge

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012