The Abergavenny-based civils contractor drove revenue up by nearly 50% last year to £154m, compared to sales of around £80m in 2012.
The rise in orders saw pre-tax profits double to £2.3m and lifted the firm’s head count by over 10% to just under 600 employees.
The firm, which ranks in the country’s top 20 civil engineering contractors, saw rail industry revenue double to £29m in 2016, according to latest results for the privately-owned company.
Main stream civil engineering work turnover rose 37% to £123m.
Director Alun Griffiths said the rail division would continue to be a key area for the firm as it pursued further joint arrangements to secure work.