BAP Almirante Grau (CLM-81)

BAP Almirante Grau (CLM-81) is a De Zeven Provinciën-class cruiser in service with the Peruvian Navy. Completed for the Royal Netherlands Navy in 1953 as HNLMS De Ruyter (C801), it was acquired by Peru in 1973. Since then, it has served as the fleet flagship of the Peruvian Navy. The Almirante Grau underwent a major modernization program between 1985 and 1988 during which it was fitted with new weapons and electronics. It is currently the last gun cruiser in service in any navy.

Acquisition
The Almirante Grau was completed for the Royal Netherlands Navy in 1953 as HNLMS De Ruyter. After two decades in service, she was decommissioned in 1973, and in the same year the Peruvian Navy bought the ship as a counter to the acquisition of the Swedish cruiser Gota Lejon by the Chilean Navy. Renamed Almirante Grau, in honor of the Peruvian Admiral Miguel Grau, she arrived to its new homeport of Callao on July 11, 1973. The Almirante Grau became fleet flagship replacing a former cruiser of the same name (the ex-HMS Newfoundland) which was renamed Capitán Quiñones.

Modernization
From 1985 until 1988, she underwent a major modernization program by Amsterdam Naval Services (ANS) at its shipyard in Amsterdam, period during which she was denominated Proyecto de Modernización 01 (Modernization Project 01) or PM-01. Her role as flagship was assumed by her sistership Aguirre as Almirante Grau. Both ships regained their former names when the ex-De Ruyter reached Callao on February 15, 1988.

The upgrade program carried out in the Netherlands included the following:
 * Fitting of the Signaal SEWACO Foresee PE combat management system
 * Fitting of a Signaal DA-08 surface-search radar
 * Fitting of a Signaal LW-08 air-search radar
 * Fitting of a Decca 1226 navigation radar
 * Fitting of a Signaal STIR-24 fire-control radar
 * Fitting of a Signaal WM-25 fire-control radar
 * Fitting of two Signaal LIROD-8 optronic directors
 * Fitting of the Signaal Rapids ESM system
 * Fitting of the CME Scimitar ECM system
 * Fitting of two Matra Défense Dagaie decoy launchers
 * Fitting of one Matra Défense Sagaie decoy launcher
 * Fitting of a Link Y data link
 * Fitting (towers) of two Bofors signal amplifiers, including aiming and firing limitation
 * Removal of four twin Bofors 57/60 mm gun mountings
 * Removal of the CWE-610 hull sonar

Further work was carried out by SIMA dockyards in Callao as follows:
 * Eight Otomat Mk 2 SSMs were fitted in 1993
 * Two OTO Melara Twin 40L70 DARDO compact gun mountings were fitted in 1996, replacing four single Bofors 40/70 mm gun mountings

Currently, the Almirante Grau is the last gun cruiser in service in any navy (although it has the capabilities of firing Otomat guided missiles, plus its main armament), and Peru is one of only three countries to operate cruisers today, along with the United States and Russia.