Bury Bar Frame locomotive

The Bury Bar Frame locomotive was an early type of steam locomotive, developed at the works of Bury, Curtis, and Kennedy.

By the 1830's, the railway locomotive had evolved into three basic types - those developed by Robert Stephenson, Timothy Hackworth and Edward Bury.

A major problem was the effect of their weight on the track of the time. Although the engines were much smaller than before, they were increasing in size as more power was needed.

Robert Stephenson had developed the "Patentee" with an extra pair of wheels to distribute the weight. However this brought problems in that the extra length affected road-holding on curves.

Such locomotives used a heavy, rigid frame of timber sandwiched between steel plates. Bury adopted a different approach by keeping to two axles and fabricating a bar frame consisting of two bars approximately 18 inches apart. The top one was of rectangular cross-section, while the lower was round.

Bury engines were also notable for their round topped "haystack" fireboxes and a high boiler pressure for the time of 120 psi. The main problem with them were the breakage of the crank axles associated with the use of inside cylinders.

While criticised for their perceived lack of strength and power they were fast and held the road well. The design was emulated by a number of manufacturers and they lasted on the London and Birmingham Railway until 1855.

In America, where there were immense distances of, often indifferent, track, they were in use until the Twentieth Century. In addition, their large fireboxes made them particularly suitable for wood burning.

In England, distances were shorter and traffic density was rising, so the trackwork was gradually improving. During the 1840s Stephenson had increased the power in his long boiler locomotive, while in 1847, David Joy introduced the Jenny Lind design.

References

* Lowe, J.W., (1989) "British Steam Locomotive Builders," Guild Publishing
* Williams, R., (1988) "The Midland Railway: A New History," Newton Abbot: David and Charles