The NBR Class M (later LNER Class D27 & D28) was an older but very similar type of 4-4-0 locomotive, commonly known as the Abbotsford class, Waverley class or "476", [2] and a pioneering 4-4-0 design by Dugald Drummond. A total of 12 were produced.

The Drummond D27 & D28 (NBR Class M) 'Abbotsford' 4-4-0 Locomotives. A Midland Railway through service over the Waverley route to Edinburgh was introduced in May 1876. The existing Wheatley 4-4-0s were not powerful enough for this service, so Drummond designed his Class M locomotives as replacements.

The NBR's locomotive classification system (introduced in 1913) is not very helpful because the same letter has been applied to several different classes. The North British Railway Study Group has developed its own classification system and a list can be found here.

Although the 4-4-0 configuration was very popular for tender locomotives, it was an unpopular choice for tank engines. The LNER only had two 4-4-0T classes, both inherited from the North British Railway (NBR). These classes numbered 33 locomotives, all of which were withdrawn before Nationalisation (1948).

Dugald Drummond (1 January 1840 – 8 November 1912) was a Scottish steam locomotive engineer. He had a career with the North British Railway, LB&SCR, Caledonian Railway and London and South Western Railway. He was the older brother of the engineer Peter Drummond, who often followed Dugald's ideas in his own work.

2024年3月29日 · 丁腈橡胶（nbr），一种由 丙烯腈（ch2=chcn，简称acn）和丁二烯（ch2=ch-ch=ch2）共聚物制成的合成橡胶。 1931年，德国化学家Erich Konrad和Eduard Tschunkur为IG Farben工作，一组名为Buna N的 丙烯腈-丁二烯共聚…

根据国家标准gb5577-85规定，已采用由nbr与后缀四位数字组成，其中前两位数字表示结合丙烯腈量的低限值，第四位数字表示门尼粘度低限值的十位数字。

丁腈橡胶的性 能主要取决于其中的ACN成分 (一般占18％-50％)，ACN含量 高于50％则具有很强的耐矿物油与燃油的能力，但其在低 温时的弹性、压缩永久变形率就变差了；丁二烯较高的配 方 (如达到78％)，则具有良. 1.3丁腈橡胶 (NBR)1.3.1 分子结构 (CH CH= CH CH )XCH CH) (CH CH CNCHICH21.3.2 理化性能丁腈橡胶是丙烯腈 (ACN)和丁二烯的共聚物。 丁腈橡胶的性 能主要取决于其中的ACN成分 (一般占18％-50％)，ACN含量 高于50％则具有很强的耐矿物油与燃油的能 …

一般nbr配方采用半有效硫化体系，例如：tt/cz 1.5/1.5phr,这种硫化体系,具有耐热性较好的效果,sul/ts压缩歪和焦烧最优.sul/dm(cz)拉伸强度好,用载硫剂可获得优良的压缩永久变形, 镉镁硫化耐热150℃,过氧化物也可耐150℃高温.且压缩永久变形最小,但撕裂差,活性用zno-a/st ...

The North British Railway (NBR) Class N (LNER D35) locomotives were designed by Holmes specifically for the West Highland Railway which opened in 1894. Two batches of six were built in 1894, and would appear to have been initially sufficient for the West Highland Railway.