Water heating is a process well-researched, even for mobile solutions: for more than 200 years, talented engineers from leading companies developed steam locomotives – the symbol of high-tech until middle of 20th century. We named our high-pressure water-heating module after the world's largest mass-produced steam locomotive, the UP 4000
(overall length 132 ft 9 1⁄4 in (40.47 m)), better known as the Big Boy
- a nickname it acquired after an unknown worker scrawled "Big Boy" in chalk on its front. Big Boy locomotives were built to haul freight over the Wasatch mountains - the task beyond his brethren. To heat tens of gallons of pressure water per minute is as daunting task for conventional heating devices, but it is easily solved by our Big Boy!