The Custom Locomotive Works in Chicago constructed a pair of miniature F-7 A diesel locomotive units for the Michigan AuSable Valley Railroad over a period of nine months.
The front locomotive contains the engine while the slug unit balances the weight.
The units have a combined weight of 11,000 pounds and length of 30 feet (9.1 m) long; they are 58 inches (1,500 mm) high.
The powered unit has an 80 hp Perkins diesel engine driving 16 wheels and supplying power to an air-brake system.

Locomotive No.
5661 is a 4-6-4 oil-fired steam engine, known as the "Hudson", built in 1961 by E.C. Eddy of Fairview.
The locomotive originally ran on the Pinconning and Blind River Railroad.
It now runs on the AuSable on selected Sundays and holidays.
 The Hudson steam locomotive was restored circa 2002.

The trackage was laid by family and friends.
 It is serpentine, sometimes with parallel and crossing tracks, making a surprising 1.5 miles (2.4 km) trip, approximately 18 minutes long.
 The railroad uses over 5,500 railroad ties.
 In 1995 four switches were added to the route.
The Custom Locomotive Works in Chicago constructed a pair of miniature F-7 A diesel locomotive units for the Michigan AuSable Valley Railroad over a period of nine months. The front locomotive contains the engine while the slug unit balances the weight. The units have a combined weight of 11,000 pounds and length of 30 feet (9.1 m) long; they are 58 inches (1,500 mm) high. The powered unit has an 80 hp Perkins diesel engine driving 16 wheels and supplying power to an air-brake system.
Locomotive No. 5661 is a 4-6-4 oil-fired steam engine, known as the "Hudson", built in 1961 by E.C. Eddy of Fairview. The locomotive originally ran on the Pinconning and Blind River Railroad. It now runs on the AuSable on selected Sundays and holidays.  The Hudson steam locomotive was restored circa 2002.
The trackage was laid by family and friends.  It is serpentine, sometimes with parallel and crossing tracks, making a surprising 1.5 miles (2.4 km) trip, approximately 18 minutes long.  The railroad uses over 5,500 railroad ties.  In 1995 four switches were added to the route.
Michigan AuSable Valley Railroad