Tank destroyers

[Debrody]

I dont know so much about tanks. WHat was the tank-destroyers advantage against the normal tanks they were developed from? There were several attempts in the ww2 to modify existing tanks, must be a reason why they did it.

[E25280]

I dont know so much about tanks. WHat was the tank-destroyers advantage against the normal tanks they were developed from? There were several attempts in the ww2 to modify existing tanks, must be a reason why they did it.

For most German and Russian TDs, it was simple economics.  Cheaper and faster construction.  You could also potentially get a more potent weapon mounting it directly to the hull vs. the turret they replaced (e.g. the 75mm gun on the Hetzer).

[Ack-Ack]

In the US Army, it was due to doctrine.  US armored doctrine stated that tanks were to primarily support troops while tank killers like the M-18 primary role was to hunt and kill other tanks. 

ack-ack

[SmokinLoon]

Most of the time when a vehicle, be it aircraft or ground based, is designed for multiple roles it is going to be more expensive because it has to cover more areas of expertise.  Also, when trying to cover all the bases it typically is not able to do them all well, either. 

A tank destroyer, be it an M10, M18, Jagdpanzer V, Su-85/Su-100, Firefly, Archer, etc, is usually less able to deal with infantry due to fewer MG's (if any) and a less then average HE shell (typically).  As such, they stood off and searched for enemy armor to engage, not enemy infantry.   

[MiloMorai]

In the US Army, it was due to doctrine.  US armored doctrine stated that tanks were to primarily support troops while tank killers like the M-18 primary role was to hunt and kill other tanks. 

ack-ack

As well as vehicle like the M3 half-track with a 75mm gun.

[Debrody]

hanks for answering 
 

[Shiva]

For most German and Russian TDs, it was simple economics.  Cheaper and faster construction.  You could also potentially get a more potent weapon mounting it directly to the hull vs. the turret they replaced (e.g. the 75mm gun on the Hetzer).

A larger-caliber, higher-velocity gun than you could fit in a turret limited by the turret ring you could fit to the hull, and you would still be able to put the crew behind comparable armor. You gave up flexibility, though; a jagdpanzer was much better suited to being pre-sited under cover with sight lines to avenues of advance. This was why, although StuG conversions appeared relatively early, Germany didn't start fielding jagdpanzer designs in any great numbers until it started fighting a defensive war.