What is a trencher? A What is a trencher? A trencher is a special machine used for digging trenches. It is often used in construction and road building projects. Tag: Trenching Related Posts:GM 140 H as excavator trencher track constructionTrenching with trenchers and Unimog trencherGM 1 AF - Trencher for mounting TrenchmasterTrenchers: Versatile applications for efficient trenchingTrenching service GM 140-AFH - 600How do you choose the right trencher?