The Turkish Navy has successfully completed the modernisation of its AY-class submarines, TCG Doganay (S-351) and TCG Dolunay (S-352).
Started in 2011, the modernisation project included the renewal of electronic support, attack and search periscopes, and inertial navigation systems.
Ankara-based defence technologies company STM was the prime contractor for this navy submarine project. Both vessels have been delivered to the Turkish Naval Forces.
This project is the first modernisation programme of Turkish submarines conducted to be performed by a civilian company.
According to STM, this project is significant as it improves the capacity of the Turkish Naval Forces and also increases the participation of Turkish defence industry companies in military projects.
Upgrades were carried out at the Turkish Navy's Golcuk Shipyards Command south-west of Istanbul on the Marmara Sea coast.
The AY-class submarines modernisation contract was signed between STM and Turkey's Undersecretariat for Defence Industries in March 2011.
The contract included replacement of existing Kollmorgen periscopes with Zeiss models of either SERO 400 or OMS 100, Bosphorus Naval News reported.
In addition, it covered installation of a new inertial navigation system from Raytheon and an ESM system from Aselsan, ARES-2N.
TCG Doganay and TCG Dolunay are two of the first modern submarines built in Turkey.
The 55.9m-long and 6.2m-wide AY-class submarines have a displacement of 1,185t. They are capable of cruising at a maximum speed of 11k and able to accommodate a total 38 personnel.
The oldest and newest AY-class submarines were commissioned 34 and 20 years ago, respectively.
Image: Turkey's AY-class submarines TCG Doganay and TCG Dolunay. Photo: courtesy of TM Savunma Teknolojileri Mühendislik ve Ticaret A.S.