Sometime back when initial reports containing specification of Arjun Mk2 came out, a pertinent question was raised as to why Arjun Mk2 weighs 67 tonne. Forum members offered various reasons but it was inconclusive whether the ERA and ploughs alone would have caused 8.5 tonne gain in weight. I am making a guesstimate of the possible reasons why Mk2 weighs what it weighs and related implications:
A. Additional protection by use of ERA
B. Limitation of the older Renk 304a(60 tonne all up weight of tank) has been overcome with new transmission
C. Mine ploughs have been included
D. Trackwidth has gone up to keep the ground pressure same inspite of increase in weight.
E. The maximum speed has come down from 72 kmph to 58.5 kmph while retaining or increasing the peak acceleration
F. Weight class has gone above MLC 60
Arjun Mk 1 - 58.5 tonne?
1. ERA and other protections - 5.0 tonne
2. Mine Ploughs - 2.0 tonne
3. Additional weight of new power pack - 1.0 tonne
4. Additional electronics/improvements - 0.5 tonne
All up weight Arjun Mk 2 - 67.0 tonne
This blog post(old) carries some details what Mk 2 might be.
http://scienceniranjan.blogspot.in/2012 ... arjun.html
A quote from above link from what Director CVRDE had said during the interview reveals an interesting data point.
At present, the army has decided to induct 118 Arjun Mk-2 tanks instead of 124. This is the result of a policy decision that will see the war reserve for all armoured regiments in the future being reduced by three.