T47 37mm 试验火炮介绍

Author: CaptianNemo  Source:http://ftr.wot-news.com/2014/10/31/t47-37mm-experimental-gun/

The T47 37mm Experimental Gun was provided by Division 1 through the Franklin Institute. The gun is essentially a modified 40mm Bofors gun (Navy Speciation) which fired a series of different projectiles using different primers and powders. Overall length was 88.58 inches.

T47 37毫米实验炮由第1师通过富兰克林研究所提供。炮本质上是一种改良的40毫米博福斯炮(海军型号)，使用不同的底漆和发射药发射一系列不同的弹药。总长度为88.58英寸。

The barrel is chromium-plated and was made by boring a 40mm(Bofors) tube for 37mm and chambering it for a standard 40mm(Bofors) cartridge case necked down to accommodate a 37mm projectile. The first gun barrel was mounted on a standard 57mm carriage and then sent off to Aberdeen Proving Grounds for testing. A second gun barrel was shipped off to Division 1 , NDRC ballistic firing range at Carderock, Maryland for ballistic tests. The second barrel failed (on round number 51) after the chromium plating failed and it was determined that the plating was too thin and it notes in the report that it was recommended that another (third) barrel be produced with the correct chromium plating thickness. The report does not say if a third barrel was produced.

枪管是镀铬的，通过为37mm枪管镗孔（boring）一根40mm博福斯炮管并将其装进一个标准的40mm博福斯弹壳内以容纳一枚37mm弹丸。第一炮管安装在一个标准的57毫米炮架上，然后送到阿伯丁试验场进行测试。第二个枪管被运往马里兰州卡德洛克的国家发改委弹道射击场第1师（Division 1 , NDRC ballistic firing range at Carderock, Maryland ）进行弹道测试。在镀铬失败后，第二根枪管在第51轮射击测试时失败了，并被确定为镀层太薄，报告中指出建议生产另一个镀铬厚度正确的第三根枪管。报告没有具体说明最后是否生产了第三根枪管。

The entire propose of the gun was to test pre-engraved projectiles combined with chrome plating the barrel which had been shown to extend the velocity life of the gun. The projectiles are made of Parco-Lubricated Steel which is where the surface of the projectile is treated with an Iron Phosphate coating.

该炮的全部建议是测试预先开槽的弹头与镀铬的枪管相结合，这已被证明可以延长炮的速度寿命。弹丸由parco润滑钢制成，弹丸表面用磷酸铁涂层处理。

The chamber volume was 31.43 cubic inches with a capacity of 29.9 cubic inches. The travel of the projectile from seating to ejection 73.96 inches(1878.584mm) another part of the source document lists projectile travel length as 76.58 inches(1945.13mm) which would produces a 50.77 calibers to 52.57 long barrel.

弹膛体积为31.43立方英寸，容量为29.9立方英寸。弹药后座的行程为73.96英寸(1878.584mm)，源文件的另一部分列出了弹药行程长度为76.58英寸(1945.13毫米)，这意味着将产生50.77口径到52.57长的枪管。

For test purposes the Experimental T47 was tested with a range of 37mm projectile weights from 1.34lbs to 1.92lbs. Six different projectiles in all. Out of the 12 results posted 1 is 1.92lbs and 1 is 1.34lbs the majority is 1.62lbs.For the 37-mm projectiles the velocities range from 3,260(50% Service Charge) to 3,870(100% Service Charge) fps for projectiles weighing 1.92lbs to 1.34lb. The 1.62-lb pre-engraved projectile at the muzzle had the velocity of about 3,500 fps.

为了测试目的，实验T47在37mm弹丸重量范围从1.34磅到1.92磅之间进行了测试。总共六种不同的弹头。在发布的12个结果中，1个是1.92磅，1个是1.34磅，大多数是1.62磅。对于重量为1.92磅至1.34磅的37毫米炮弹，其速度范围为3,260 fps(50% Service Charge)至3,870 fps(100% Service Charge)。1.62磅预刻弹的炮口初速约为3,500 fps。

The six lands for the pre-engraved projectile had a constant twist of 24 calibers per turn. (1 turn in 24 calibers although another part of the same document gives this same info as 1 in 25).  The groves were 0.030 inches in depth with the lands pointed on a 30 degree slope at the origin of rifling and by changing the feed mechanism to prevent rotation of the previously indexed round.  The projectile in turn had six corresponding splines pointed with a 30 degree slope to match the lands.  The rounds were aligned in the case so that proper indexing of the case would automatically index the round.  The case was the standard 40mm(Bofors) case, necked to fit the 37mm pre-engraved projectile.  A guiding groove was cut in the base to guide the case on a vertical aligning track and an extension of this groove was cut in the edge of the flange to guide the case along a horizontal track in the tray.

这段说的啥看不懂不翻了

For the 37mm projectiles the observed values of deceleration range from 600 ft/sec2 to 1,250 ft/sec2 depending upon the service charge used, 50% and 100%. (The range is 500 ft long and is horizontal. Concrete piers for the support of velocity ‘solenoids’ are located at 50-ft intervals along the range.) The deceleration of 3-in. projectiles on the range has been computed for each successive trio of solenoids, and for the first arid the last pair of solenoids.

Maximum pressures in the 37mm gun ranged from 52 to 64 kilopounds psi.The two powders tested in the gun were M-1 powder (low flash-intensity) and M-5 powder (high flash-intensity). On several rounds pictures of the 37mrn projectiles in flight were made about 75 ft in front of the gun by illuminating the projectile with a “microflash”.

对于37mm弹丸，观察到的减速值范围从600 ft/sec2到1,250 ft/sec2，这取决于所使用的service charge，50%和100%。(射程是水平的500英尺。用于支撑速度“螺线管”的混凝土桥墩位于沿着该范围的50英尺间隔处。3-in的减速。射程上的弹丸已被计算为每个连续的三个螺线管，并为第一个和最后一对螺线管😵😵。

37毫米炮的最大压力范围为52至64 kilopounds psi。枪中测试的两种发射药分别是M-1(低闪光强度)和M-5(高闪光强度)。在几个回合中，37mm炮弹的飞行照片是在炮前约75英尺处用“微闪光”照亮炮弹拍摄的。

Armor penetration is not mentioned specifically but early on in the document a ‘current gun’ is mentioned, but not named, that penetrated a 3-5/8 inch plate of Class “B” Armor at 20 degrees incidence at a velocity of 3,440 fps. Which does fits the profile of the T47 gun. To be honest the anti-armor performance is not that great compared to the 37mm LJ and 37mm APDS. Both of which will be reserved for another time.

没有特别提到穿甲性能，但在文件的早期提到了一门“current gun”，但没有命名，它以20度射角以3440 fps的速度击穿了一块3-5/8英寸的B级装甲。这符合T47火炮的概述。老实说，与37mmLJ和37毫米APDS相比，它的反装甲性能并没有那么好。这两个都要留待以后再用。

Source of text and Photos: Summary Technical Report of Division 1, NDRC. Volume 1 Hypervelocity Guns and the Control of Gun Erosion, January 1946.