"Ron's photo above is what I've heard referred to as a "ballasted deck bridge". Don't know why those were done that way, but I've seen one out here in California on the old ATSF Lake Elsinore branch"
Hi Matt, The reason ballasted deck bridges are popular is that they make it easier to reballast the route and blend the new ballast into the bridge track. If the rails are spiked to the bridge then it's harder to match them to a new layer of ballast.....DaveB
