Another consideration with the crosshead engine is in the ease of maintenance when pistons have to be pulled from the cylinder. The piston rod is mounted on the underside of the piston and connected to the crosshead by a single nut.
The pistons on these engines are generally in the order of 600 - 800mm and weigh in the region of half a ton.
wikipedia.org dumped 2003-03-17 with terodump