In the 60s, and 70s most locos were known by their manufacturers names and power classification. Named locomotives generally were nicknamed after the naming series, for example Warships, Westerns, etc
The class 40s were probably unique in not being known other than by their manufacturer/type, although I hear them referred to once or twice as Ocean Liners, but never since then.
It is a shame that modern names are generally very poor in comparison, and mostly stupid.
Here is the list of what I have known them called as. Most of these are from the 60s and 70s
01: Barclay
02: Yorkshire
03: Flower Pot
04: Drewery
05: Hunslett
06:Barclay
07:Ruston
08: Jocko / shunter
13: Master and Slave
14: Teddy Bear
15:BTH Type 1
16: North British Type 1
17: Clayton
20: Type 1 / English Electric Type 1 / Chopper
21: North British Type 2
22: Baby Warship
23: Baby Deltic
24: Type 2 / Bo Bo.
25: Type 2 / Sulzer Type 2 / Bo Bo
26 & 27: Birmingham / Type 2 Birmingham
28: Metro-Vick / Co Bo
29: North British Type 2
31: A1A / Brush 2 [D5500 – D5519 (31001 to 31020) Toffee Apple / Skinhead]
33: Type 3 Birmingham / Crompton
35: Hymek
37: Type 3.
40: English Electric / English Electric Type 4 / Whistler
42: North British
43: Warship
44: Peak
45: Peak / Crompton Parkinson
46: Peak
47: Type 4 / Brush 4 / Four & Half / Sulzer
50: English Electric Type 5 / Hoover
52: D1000 / Western / WR Hydraulic
55: Deltic / Type 5
56: Christmas Tree
76: EM1 / Tommy
77: EM2 / Tommy (although technically only 76s were Tommies)
81-85: Early electrics / Roarers
86: AL6
87: Electric Scot
AC EMUs known originally as AM1 to AM10
SR EMUs known originally by various names such as BEP/BIG/2BIL/CEP/CIG/4COR/EPB/HAL/HAP/SUB/REP/VEP/4TC
DMUs generically known as "Bog Units", individually by their makers names, eg, Cravens, MetCam, Pressed Steel. Some were known by their build type, such as Light Weights, or by their service use, eg, Cross Country / Trans Pennine.
Single sets (Class 121) were known from early on as "Bubble Cars", after the small car of that name.