We were on I-55 and had a blow out on my Flagstaff HW27SC. I had a 4 ton bottle jack and had thrown in a 4 ton scissors jack at the last minute before we left. I also carry about 8 pieces of 3/4" plywood about 6" X 6". Well the bottle jack was too high to fit under the axle behind the tire and I could not operate the scissors jack in a very awkward position. I had to put the bottle jack under the frame behind the tire but it did not have enough lift, so the scissors jack went under the frame before the tire to get high enough to change the tire. The ground was soft and I used all of my plywood squares. My sockets were too shallow to remove the nuts holding the spare tire to the mount but I made do with an an adjustable wrench. All very exciting on the edge of the interstate with the trailer rocking with each passing vehicle. Just glad it was not on the driver's side as there was no room to pull any further off the highway and I would have been in the roadway. I will be replacing my jacks with a 4 ton hydraulic floor jack and a piece of 3/4" plywood maybe 30" X 10" for it to ride on. A little extra weight and room but well worth it if needed. I think that jacking it up were I had to may have bowed the frame somewhat as the top pins in my slide no longer line up as they should. Will have to work on that. Just saying to be sure that you are well prepared for this type of issue as it could be life threatening in certain situations.