Type 051B destroyer

The Type 051B Luhai-class is a class of destroyer built by the People's Republic of China. It consists of only one ship, No.167 Shenzhen. When Shenzhen was commissioned into the People's Liberation Army Navy Surface Force in 1998, it was then, the largest surface combatant that China had ever built. It resembles in many ways an enlarged version of the Luhu-class destroyer, and is one of the first PLAN ships with a slope-sided hull to reduce radar signature. The 051B was succeeded by the domestic Type 052B, discounting the 4 Soviet built Sovremennyy-class destroyer China purchased in the interim.

History

Shenzhen was laid down by the Dalian Shipyard in May 1996. The Shenzhen was intended to be an experimental vessel with improvements over the Luhu-class' in terms of modular construction and stealth. The ship is powered by two indigenous steam turbine engines, due to Dalian Shipyard's experience in steam turbine construction and that Chinese domestic research and development on marine gas turbines had not yet matured. The displacement of the Luhai-class is 2,000 tons heavier than the Type 052 destroyer, Luhu-class. Shenzhen was launched in 1997, although official revelation of the ship's existence did not come until the year following its commissioning. The chief designer of this class is academic, Mr. Pan Jingfu (潘镜芙), who is also the designer of both the Type 051B's predecessor and successor.

Type 281 radar

The Type 281 radar was a British naval early warning radar developed during World War II. It replaced the Type 79 as the Royal Navy's main early warning radar during the war.

The prototype system was mounted on the light cruiser HMS Dido in October 1940. This radar used a frequency of 90 MHz, a beamwidth of 35°, and a wavelength of 3.5 metres. It required separate transmitting and receiving antennas that were rotated by hand. For long-range warning the radar used a 15 microsecond pulse at a power level of 350 kW that gave a detection range up to 110 nautical miles (200 km; 130 mi) for aircraft. For tracking surface targets it used a 2–3 microsecond pulse at 1 MW that gave a range up to 12 nautical miles (22 km; 14 mi). A second set was installed in January 1941 aboard the battleship HMS Prince of Wales and production began of another 57 sets with the first deliveries occurring the following month. This set also had a secondary aerial and surface gunnery capability and used a Precision Ranging Panel. The Type 281 ranging system allowed the user to select either a 2,000 yards (1,830 m) to 14,000 yards (12,800 m) or a 2,000 yards (1,830 m) to 25,000 yards (22,860 m) range display with range accuracies of 50 yards (50 m) or 75 yards (70 m) RMS, respectively. Aerial target ranges were passed directly to the HACS table (fire control computer).

Type

Type may refer to:

In philosophy:

In theology:

In mathematics:

In computing:

In sociology:

Other:

Type (designation)

The word Type followed by a number is a common way to name a weapon or product in a production series, similar in meaning to "Mark". "Type" was used extensively by the Japanese and Chinese militaries beginning in the 1920s, and is still in current use by the militaries of both nations. The United Kingdom uses a type number system for much of their military equipment. Many other nations use the word "Type" to designate products in a series.

Japan

The Imperial Japanese Navy (IJN) began using the Type-Number System in 1921 to designate aircraft accepted for production. The numbers used after the word "Type" were based on the number of years that the Emperor Taishō had reigned. Since his reign began in 1912, an aircraft ordered into production in 1921 would have been called "Type 10", the tenth year of the emperor's reign. At the end of 1926, the emperor died, leaving his son Hirohito as the Emperor Shōwa, and the numbering system was reset to mark the new emperor's reign.

In 1929, the government of Japan adopted a new system based on the imperial year. Aircraft ordered for production from 1929 onward were assigned the last two digits of the year marking the continuity of Japanese emperors. 1929 was the 2589th imperial year, so aircraft ordered that year were designated "Type 89". 1940 was the 2600th year, and the IJN numbering system was reset to single digits. New aircraft were designated 0 (zero). The well-known Mitsubishi A6M Zero was ordered into production in 1940 as the IJN "Type 0 Carrier Fighter" (Rei shiki Kanjō sentōki, 零式艦上戦闘機), and was popularly called the "Zero" because of its type.

Glossary of numismatics

This article is a collection of Numismatic and coin collecting terms with concise explanation for the beginner or professional.

Numismatics (ancient Greek: νομισματική) is the scientific study of money and its history in all its varied forms. While numismatists are often characterized as studying coins, the discipline also includes the study of banknotes, stock certificates, medals, medallions, and tokens (also referred to as Exonumia).

Sub-fields or related fields of numismatics are:

A

B

C

D

E

F

G

H

I

K

L

M

N

O

P

Q

R

S

T

U

V

Y

Z

References