The Midland was blessed, in that George Stephenson had built its main lines with very shallow gradients while its main rival the LNWR had to cope with the hilly country north of Lancaster. The Midland favoured building large numbers of relatively small, low-powered engines to standardised designs. Each engine was cheaper to build and run than a larger equivalent and while more locomotives were required, the Midland's Derby Works was able to achieve economies of scale. The Midland found that on the majority of its well-graded lines a single small engine was sufficient, and that it was more efficient to add either more trains of a shorter length to handle greater demand or to employ multiple small engines (two or three) when heavier trains were needed. This was deemed preferable to building a small number of large engines for the routes and duties that required them which did not fit into Derby's standardised production and risked being underutilised and incurring expensive running costs unnecessarily. Indeed, the Midland's operations were often based around keeping even its small engines lightly loaded at a time when other railways were not only building larger, more powerful locomotives but working them to their maximum capacity with the heaviest trains possible. The Midland's philosophy was to keep individual train weights as low as was practically possible and run more trains, providing short-term economies in fuel consumption and wear-and-tear on the locomotive, which in the long term this meant that Midland locomotives generally enjoyed longer service lives than hard-worked contemporaries on other railways. This was one reason why the relatively undersized standard Midland axle bearing was successfully retained for so long into the 20th century - under Midland operating practices the loads imposed on the bearing by a low-powered locomotive working well within its capabilities was minimised.