DW-saddle tanks are attached to boilers with brackets in different configurations. They appear to be bolted to the tank and then to the boiler...I don't know if the bolts go into the boiler or just into the lagging...that may not be the best way to mount one, however.
Here's a photo of 20" gauge Copperhead out in Clifton, AZ-shows an "L" bracket behind the smokestack that holds the tank on. This one looks like it is riveted on to the smokebox. There are other brackets under the tank attaching to the boiler, but my photos are a little fuzzy of them. I hope you can get an idea from this shot.
Looking at this photo makes me want to fire up the motor home and get out there again. Clifton is only about 40 miles from Mogollon and all that is about a million miles away from Dallas!
____________________ It doesn't matter if you win or lose, its' how you rig the game.
Nothing of any consequence is attached to the lagging, which is what looks like the outside of the boiler. The lagging is only a sheetmetal cover, to hold the insulation--asbestos blocks, in the bad old days-- to the boiler. The smokebox is not insulated, and that is why you see rivets on the smokebox, but not on the boiler The cylinders are insulated also.
Not part of Dwayne's question, but in movies or videos of steam locos in action, steam can be seen escaping form the bottom of the cylinders when the loco starts moving, then dissapears. The reason for this, is that when the loco is standing, the cylinders cool down, and any residual steam condenses back into water. Water is incompressible, and to avoid having water trapped in the small area between the piston and the end of the cylinder when the loco starts to move, small valves in the bottom ends of the cylinder are opened (from the cab) to blow any water out. If enough water were trapped in the cylinder, and the loco started quickly enough--or the wheels spun (same thing) the water can, and has on some occasions, push the end right off the cylinder--a ring of large bolts not withstanding.
Just part of choo-choo 101
____________________ Fix it again, Mr Gates--it still works!"
Im not sure if this is what you were looking for, but it looks like the side supports/mounts for the saddle tank on what is left of this narrow gauge Porter are attached to the heavy straps (i'm sure there is a better term) that go around the outside of the boiler.