The ALCO S-2 and S-4 are 1,000-horsepower (746 kW) diesel electric switcher locomotives produced by ALCO and Canadian licensee Montreal Locomotive Works (MLW). [1] Powered by turbocharged, 6-cylinder ALCO 539 diesel engines, the two locomotives differed mainly in their trucks: the S-2 had ALCO "Blunt" trucks; the S-4, AAR type A switcher trucks.

The ALCO S2 and S4 were 1,000 horsepower diesel electric switchers produced by ALCO and Canadian licensee Montreal Locomotive Works (MLW). The two locomotives differed only in trucks, with the S-2 using ALCO "Blunt" trucks, and the S-4 using AAR type A switcher trucks. Both were powered by ALCO 539 turbocharged, 6-cylinder diesels.

Click on a locomotive to view pictures Roster Options: Main Roster Group by model Show All thumbs All S4s PRR Rolling Stock

The 4-6-4 arrangement was seen on the PRR only on electric locomotives. As a steam locomotive arrangement, it was poorly suited to the PRR's mountainous terrain, wasting much potential adhesive weight on non-driven wheels. That it was so widely used by the rival New York Central would also likely have factored against PRR adoption.

This roster outlines the dieselization of the Pennsylvania Railroad, from 1937 through 1968. It is presented in two parts: First and Second Generation Locomotives. Photo: PRR U25B #2530 …

PPR管分为S3.2、S4、S5、S6.3这个是表示PPR水管的管系列，管系列是区分PPR水管承压能力的一个参数，由此可以判断PPR水管的承压能力。 每一种管径规格的的PPR水管都会对应不同的管系列，以此区分相同管径下，不同壁厚的水管的承压能力。

Photo Caption: "Alco S-4 #8434, 1000-hp, at Detroit, Mich." Shown here is Pennsylvania Railroad engine #8434, an AS-10 switcher built by the American Locomotive Company in February of …

Since the ICC had mandated PRR control of the New Haven, the Lehigh & Hudson River was included to provide for a direct PRR New Haven freight connection via Maybrook, ny and the …

There are numerous individual ALCO locomotives that are preserved in museums or heritage railways. In particular please see sublists List of preserved locomotives in the United States and List of preserved locomotives in Canada.

2022年3月10日 · PP-R管材有S5、S4、S3.2、S2.5等4个管系列，通常热水管道有S3.2、S2.5两个管系列，冷水管道系统用S5、S4、S3.2 三个管系列。 在管道系统设计中，按不同使用要求，安全系数可取1.25或1.5。