(1790 - 1859) was the County Surveyor of Montgomeryshire
from 1817, and designer of a number of masonry arch bridges
over the River Severn
Penson's father had been County Surveyor of Flintshire, responsible for a bridge at Overton-on-Dee which collapsed. Thomas Penson designed its replacement.
Penson was a pupil, along with Thomas Telford, of the architect and bridge designer Thomas Harrison. He relied on contractors to build his bridges, such as David Davies, who built Llandinam Bridge in 1846.
In February 1852, the Severn flooded, damaging a number of bridges for which Penson went on to design replacements.
Penson designed a two-span cast iron arch bridge at Caer Howell in 1858 to replace a timber structure destroyed by floods. Against his advice, a suspension bridge designed by James Dredge had been built in 1854, only to collapse four years later under the weight of three lime wagons, killing one man. He also designed a church at Newtown, Powys, and Montgomery jail.
Other structures credited to Thomas Penson include:
- Caersws Bridge, at Caersws, 1821, three elliptical masonry arches
- Long Bridge, at Llanidloes, 1826, three-span masonry arch bridge, replaced a wooden bridge
- Long Bridge, at Newtown, 1827, masonry arch widened by Penson with cast iron arches in 1857
- Felindre Bridge, at Mount Severn, 1848, segmental or elliptical masonry arch bridge
- Short Bridge, at Llanidloes, 1849, masonry arch bridge
- Brynderwen Bridge, at Abermule, 1852, 33m span cast iron arch bridge, Grade 2 Listed
- Cilcewydd Bridge, 1861, masonry arch bridge
- Breese, Gwyndaf, The Bridges of Wales, Gwasg Carreg Gwalch, 2001, ISBN 0-86381-667-3
- Witts, Chris, A Century of Bridges, River Severn Publications, 2nd ed., 1998, ISBN 0-9532711-0-2