Something interesting about Merkava III's armor protection(in Chinese):
Some of these images are come from Chinese course book《装甲防护技术基础》（The basic technology of armor protection）, and others are come from this issue： http://www.cnki.com.cn/Article/CJFDTotal-BQZS200108004.htm
The main author of these two sources is one of the chief tank designers in China. Mr.Zhang has presided over a design of front-engine tank scheme under the frame of Chinese 3rd gen MBT, but there was little info refer to these history)
Photo of Mr.Zhang and General Tal.
The cast turret base and weld frame.
Special armor covered, those colored parts most likely are heavy NERA or Built-in-ERA structure modules, while others are lighter module I guess.
T-3/4 module before shooting by a HEAT warhead of HOT missile. According to previous picture, it should be the side armor of the turret. So we can assume that the front arc of Merkava III's turret, looks likely ±30°，which can withstand more than 700mm even 800mm penetration from CE threat.
Still the T-3/4 module,before hitting by a RPG warhead.
I am confused this number as T-9/4 at my first look, but it is more likely a distorted "3". There are some reasons: (1) Its thickness doesn't seem to fit on top of the turret. (2) In this pic the threat is RPG warhead, moreover, its incidence normal angle is smaller than the previous HOT warhead, which can be used as a useful basis for judging.
Built-in ERA structure, the left side is Israeli scheme, and Russian scheme at right side.
The armor layout of tank Merkava Mk III. The solid line is base steel armor's equivalent thickness, including spaced armor array inside the hull( The table above shows the thickness and inclination of the base steel armor, unfortunately many notes are missing in the PDF) and the dotted line is the special armor's protection capability against KE ammunition, up to 450mm RHA on turret front and 350-400mm on the UFP.
Hope you guys will enjoy this post