The X-5000 Dynamometer Car was originally designed and built by the Milwaukee Road (designers Vern Green and Leonard Lentz) at the Milwaukee Shops in 1930 to measure steam locomotive output by means of a large hydraulic unit spliced into the center sill called a dynamometer unit that generates a hydraulic pressure proportional to the drawbar pull or buff (push) measured at the coupler of car.
Warren Newhauser, an Illinois Railway Museum member involved in restoring Milwaukee Road Dynamometer car X-5000, said in his own words: “Another product we used for waterproofing the roof is from a company called www.Sanitred.com. They make a “Permaflex” urethane waterproof compound that will adhere to less than ideally prepped surfaces, which is what we had. It was designed for metal roofs. They also make a calk called “Liquid Rubber Base” which can fill gaps, spaces, etc. like caulk. We have found nothing else that will seal the roof like this stuff. It is unbelievable how well it works. It literally saved our car from incessent roof leaks. Not cheap, but worth every penny too. Our sandblasting contractor uses it all the time and recommended it.”