It seems that some major departments have a basic spec they use and possibly even designed themselves, regardless of the manufacturer. It seems like some have a spec that regardless of the manufacturer, is always the same behind the cab. An example is the FDNY, having the same basic spec on their Seagrave and KME engines, ever since they began running the spec in the early 1990's. Another example are the Seagrave and Ferrara rear-mounts looking like the same spec, while the 1980's Mack CF/Ward 79's had theirs and even the 1970's era Mack CF and ALF's looked the same behind the cab. LAFD did the same with Seagrave and Pierce. Are there departments that design theor own rigs like that and send the spec to the manufacturers and if so, what other departments have their own proprietary designs?