My late Dad was Superintendent Marine Engineer for Humber Tugs and he liked taking pictures of them, lots and lots of pictures...
I thought I'd share a few. There used to be two tug companies on the Humber, Pigotts on the south bank covering Grimsby and Immingham and United Towing on the north bank covering Hull (and further afield). All the tugs on the south bank are called Lady ... and all the tugs on the north bank have "man" at the end of their name. The companies merged to become Humber Tugs and after a few more takeovers are now Svitzer (Danish?)
One name is unfortunate:
Tugs have to go into dry dock every 5 years for Lloyds of London insurance - every part of the tug is stripped and checked, even the engines are dismantled which is probably why the Seaman is in drydock.
The Humber is a busy river, Immingham is the UKs largest port by tonnage. It's also a tricky river to navigate not only does it have a fast tide (20% of England's rainfall exits through this river), it is shallow in places and those shallow areas constantly move. You need a lot of tugs, these are part of the fleet heading back through the lock gates into Immingham dock. Most of the south bank tugs are berthed at Immingham with one, maybe two at Grimsby. When Dad first started this job there was still a steam tug, the first Lady Sarah, berthed at Grimsby.
Bigger ships need a lot of nudging:
Mr Pigott, the original owner, thought that "proper" tugs needed a funnel which is why you'll see the large black central funnel on the older tugs. It block rearwards visibility, so the newer "Lady" tugs have smaller, twin exhausts mounted on each side like the north bank tugs.
Technology marches on in all fields, this tug under construction has a Voith Schneider propellor - a series of rotating "rudders" than can be moved to move the tug in any direction - modern tugs are joystick controlled. The weird looking frame under the hull is part of the Voith unit.
http://voith.com/corp-en/drives-tran...eller-vsp.html
You also get specialist tugs: for firefighting
and for deep sea towing:
Finally, a couple of pictures showing the area where my Dad felt at home (although I think he would have been happier to continue flying). I cannot recall which tug this was (sorry Dad). I used to hate the engine rooms - I've never liked loud noises; we would enter and he would start the compressor and I thought that was bad enough (the main engines were started by compressed air). He would then open a few valves for fuel oil and air and the hissing would start followed by a deep rumbling which you could feel through your feet, your stomach, your spine and the noise would climb exponentially until the engines dropped into their low idle (but it was never quiet), at which point the generators would be producing power and the lights would come on. Did I mention all this noise was in the dark? Communication was impossible (and we had no ear defenders since we only there for a short time - it's different nowadays). My Dad was 90% deaf when he passed.
The last one: how many engineers does it take to adjust the tappets? It takes 4 and 1 to photograph the work, apparently.
Postscript: I found this video of a Ruston and Hornsby diesel starting up (most of the tugs had Ruston engines - Dad had worked in the factory). It gives some idea of what it was like - although this is in the open. You had to descend into the bowels of the tug in the dark and the whole engine room would resonate, definitely not my favourite place to be.
https://www.youtube.com/watch?v=2ZBy7YcDeFk
When the mechanic opens up the engine - I could picture my Dad looking at the exhaust and frowning - if the engine was cold he would keep quiet but if was warm he would be speaking to the chief engineer - it shouldn't be smoking like that he would grumble, we need to take a look at that.