This is an attempt to overcome one of the primary problems with differing gauge systems—gauge incompatibility. However, it means that the narrower gauge network must be built to a structure gauge large enough to accommodate the loading gauge of the wider gauge equipment, negating one of the cost advantages of a narrower gauge construction. Additionally, a large wider gauge wagon balanced on a narrower gauge transporter wagon is not very stable, and is generally restricted to low speeds of 15 mph (24.1 km/h) or so.