Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment (hierarchy name)
4. Single Built Works (hierarchy name)
5. single built works (built environment)
6. [single built works by specific type]
7. [single built works by function]
8. transportation structures
9. [transportation structures by function]
10. rail transportation structures

Additional parents:

1. top of the aat hierarchies
2. Objects Facet
3. Built Environment
4. Single Built Works
5. single built works
6. single built works by specific type
7. single built works by form
8. single built works by form: massing or shape
9. towers
10. signal towers

Narrower term/s

• railroad signal houses

Anotations

Scope note:

Structures, often tower-like, from which signals are sent to control the movements of railway trains. They typically house the control equipment for signal apparatuses and switches.