Les "midship aerials" sont des échelles montées à l'avant du camion, juste derrière la cabine , d’où le terme "mid-ship". On les trouve sur des camions entre 1950 et 1970. Le haut de l’échelle est replié vers l'arrière du camion

photo : http://camionsthibault.com/Photos Pierre Thibault Canada Lte...

"Apparatus-mounted Iadders
Many apparatus are equipped with permanently mounted ladders that provide firefighters elevated access for vital firefighting tactics. Most can also provide elevated master streams. To rise and operate properly, the ladders must be stabilized with hydraulic jacks and tormentors. These apparatus are commonly called aerial ladders. Mid-ship apparatus are aerial devices mounted just behind an apparatus's cab or mid-frame with the ladder tip extending toward the rear of die apparatus. Rear-mount apparatus are aerial devices mounted at the rear of an apparatus with the ladder's tip/bucket mounted over the cab of the apparatus. "
http://tinyurl.com/midship-aerial


"Aerial apparatus purchased during the decades of the 1950’s and 1960’s were predominantly built with midship mounted turntables installed directly behind the cab of the unit. "
"Not to be outdone, American LaFrance produced their first Ladder Chief rear mount unit the following year and since that time virtually every manufacturer has offered both midship and rear mounted aerial ladders. "
http://www.emergencyvehicleresponse.com/fullstory.php?81858

"First, lets look at midship mounted aerial devices and what design features they offer. A midship aerial device provides a lower overall travel height for those departments that have reduced height bay doors, bridges or underpasses that would restrict travel. By varying the position of the turntable on the chassis frame, the overall travel height of the apparatus can be modified to meet the individual needs of the fire department. As the overall height of the vehicle gets lower the space for ground ladder storage and the useable compartment space is reduced accordingly. The NPFA requirement for enclosed compartment space on an aerial ladder or quint is forty cubic feet with a payload capacity of 2500 pounds. Unfortunately, many ladder trucks are designed to meet these minimum standards but have little or no useable space to accommodate the needed equipment and ground ladder compliment.

Midship aerial devices are generally easier to spot and position on the fire ground as the center mounted turntable allows the operator to locate the center of the turntable with the midpoint of the structure. Units which have raised roof cabs can inhibit the ability of the aerial device to operate at low angles when the device is working off the front of the apparatus. This is particularly important with mid-mounted tower ladders where it may be impossible to operate the tower at angles below thirty to thirty five degrees. While many manufacturers offer reverse slope rear walls on the cab and collision avoidance systems for the device, it is best to actually operate an identical unit at the critical buildings in your first due area to insure that what you want to purchase will actually work for you. Do not let the apparatus salesmen bring in the latest and greatest aerial apparatus, set in up in the biggest parking lot in town and tell you that your department has to have it. When was the last time you responded to a parking lot on fire? The apparatus must be taken to the down town area and you as the consumer must insist that the salesman puts the apparatus through it paces. How many aerial apparatus demonstrations take place and the salesmen never flow’s water? Too many to even count. Also Raised Cab Roofs on mid-mounted Tower Ladders should be avoided if at all possible as it will cut down the operational effectiveness of the apparatus. "
http://www.emergencyvehicleresponse.com/fullstory.php?81852




Les bras élévateurs articulés sont les grandes échelles actuelles, qui sont montées à l'arrière du camion, donc exactement à l'opposé des "midship aerials".

"Bras élévateur articulé 30 m ou 40 m
Engin armé par 2 sapeurs-pompiers équipé d’un bras élévateur articulé de 30 ou 40 mètres avec une nacelle, permettant d’accéder à des points hauts, d’effectuer des sauvetages, de descendre une victime médicalisée avec son brancard, d’attaquer un feu au moyen d’une lance-canon."
http://www.sdis67.com/fr/aovehiculesspecialises/bras-elevate...