Whitworth Library uses the Library of Congress classification system. Engineering books are located in both the main collection and reference (non-circulating) collection shelved under:
- T Technology
- TA Engineering (General). Civic engineering
- TC Hydraulic engineering. Ocean engineering
- TD Environmental technology. Sanitary engineering
- TE Highway engineering. Roads and pavements
- TF Railroad engineering and operation
- TG Bridge engineering
- TJ Mechanical engineering and machinery
- TK Electrical engineering. Electronics. Nuclear engineering
- TN Mining engineering. Metallurgy