The Night Mail

[jamie92208]

Good moaning from the duplicate page 2147, aka 2148.

 

Jamie

[jjb1970]

On 24/09/2024 at 04:36, AndyID said:

 

Cripes! That sounds like a lot of clearance. How many RPM do the props typically run? Has there been any consideration of eliminating the stern tube entirely?

 

The shaft speed will depend on ship type and what type of propeller is used. A direct drive slow speed engine with fixed pitch propeller (the norm for deep sea cargo ships) will typically have a maximum RPM of up to about 120rpm, but actual service revs will usually be much lower, 50-60rpm is pretty normal. A constant speed control pitch prop can run faster but even there they're not that much faster as the optimum for efficiency tends to be making the prop as big as you can and spinning it as slowly as you can, and higher speeds run into cavitation problems.

 

Ships are one of those technologies which can appear very crude and a bit backwards, the default for big ships of a slow speed engine with a direct drive to the prop (no gear box or clutch) hasn't changed for decades as it has defied all efforts to beat it with something more efficient. Control pitch props come into their own for ships which do a lot of manoeuvring and where ship control is much more important such as ferries, offshore support vessels or cargo ships deployed on short high rotation routes, where the drop in efficiency is outweighed by greater control.

 

The stern tube is critical as it carries the weight of the propeller, and the shaft seals for the stern tube are what stops the shaft tunnel from flooding. We have had one of those 'back to the future' moments, in the dark and dim past stern tube bearings were lignum vitae wood or even rubber and water lubricated. Then oil lubricated white metal bearings became the norm which gave far superior performance, massively tighter alignment and which if properly lubricated would last the life of the ship with no maintenance beyond periodic wear checks and seal renewals.

 

The change back to water lubrication is primarily environmental, as it eliminates oil releases. White metal stern tubes have outer seals but over time they can degrade, depending on draft and system design that means water coming in or oil going out. Engineers used to make ourselves unpopular by banning fishing over the side as one of the common causes of shaft seal damage for the main propeller and bow/stern thruster seals is fishing lines getting wrapped around the shaft. There was a horrible oil called Vickers Hydrox which was formulated to operate as an emulsion with massive levels of water content for things like stern tubes with damaged seals to try and avoid premature drydocking.

 

Some azipod manufacturers claim they eliminate the stern tube, as it's a podded propulsor outside the hull but it's rather disingenuous as they still have a bearing and seal between the motor and the propeller. You could design a fully sealed system with something like a magnetic clutch of the type used for pump drives where shaft leakage is unacceptable (such as especially toxic fluids) but it'd be a huge magnetic clutch and on balance every time it's looked at the potential problems make managing the shaft seal and shaft alignment trivial.

 

The shaft -sterntube alignment is one of those bits of building a ship that really does demand a lot of skill, and where experience comes into it's own, as it involves engines weighting several hundred tons or over a thousand tons, multiple intermediate bearings for a long shaft and the stern penetration on one of the most overbuilt parts of the ship. And it has to be right, it's one of those things if not right the problems are immense and trying to cure them hideously expensive. The guys that are good at it are one of those few categories of people where I would watch them in action and think 'that's impressive' as whereas most jobs I look at and consider it to be a matter of education and training, there are some jobs where the skill demanded really is difficult ti imagine picking up. Something that shocks a lot of tech types and instrumentation sales people is a lot of the best guys in Korea, Japan and China still use piano wire and mechanical instruments rather than lasers as they insist they can work faster that way. And despite scepticism from 'experts' they do it to the required tolerance extremely quickly.

 

The shaft is a sort of microcosm of the problems of trying to build ships in the UK, US, Europe. The Korean and Chinese guys are doing an alignment job pretty much on a weekly basis and are extremely good at it, the yards in the UK, US etc do it every few years and as often as not it's the first time for those doing it, with predictable results.

 

Crikey, this is a long one, I'd better stop, sorry.

[Flying Fox 34F]

Thinking about the good Doctor’s comments about Directors and Producers, I realised that Accountants are very similar.

Apparently, it is very straightforward to show an Organisation to be in Profit or Deficit, from the same set of figures????

 

Paul

[jjb1970]

21 hours ago, Mike Bellamy said:

 

Agreed - as long as you realise that it's a programme designed for entertainment and is not an historical documentary. Here in the UK there have been numerous newspaper articles about everything that's wrong with it . . . . . . . . 

.

 

My faith in humanity has been destroyed😢🫣

[jjb1970]

I had a reminder of why I avoid open social media yesterday. A friend attending the same meeting made a very innocuous Linkedin post complimenting someone on a good presentation at the meeting, followed by a complete muck storm and melt down from people demanding the post be removed immediately, hitting the roof about him giving moral support to the enemy blah blah blah. My friend is an academic and less cynical than I so still sees these things as an idealist. He was properly upset, my advice to him was keep your social and professional accounts separate and to be frank I'd just not do social media in the public domain as even on private accounts things can leak and suddenly become a big issue. 

 

It's not just the obvious one of outrageous posts. I get that if you are publicly associated with an organization personal conduct in public matters so making Facebook posts calling for genocide, telling racist jokes etc are  a no no (and should be anyway on the grounds of human decency) but someone somewhere will find a reason to throw a tantrum over the most innocuous things. It's a lot easier just not to bother. Our communications director keeps badgering me to join Linkedin, FB etc and I just refuse and have told her it's not negotiable and our CEO is quite happy with that (he avoids it as much as he can too, though he does do it).

[AndyID]

20 minutes ago, jjb1970 said:

 

The shaft speed will depend on ship type and what type of propeller is used. A direct drive slow speed engine with fixed pitch propeller (the norm for deep sea cargo ships) will typically have a maximum RPM of up to about 120rpm, but actual service revs will usually be much lower, 50-60rpm is pretty normal. A constant speed control pitch prop can run faster but even there they're not that much faster as the optimum for efficiency tends to be making the prop as big as you can and spinning it as slowly as you can, and higher speeds run into cavitation problems.

 

Ships are one of those technologies which can appear very crude and a bit backwards, the default for big ships of a slow speed engine with a direct drive to the prop (no gear box or clutch) hasn't changed for decades as it has defied all efforts to beat it with something more efficient. Control pitch props come into their own for ships which do a lot of manoeuvring and where ship control is much more important such as ferries, offshore support vessels or cargo ships deployed on short high rotation routes, where the drop in efficiency is outweighed by greater control.

 

The stern tube is critical as it carries the weight of the propeller, and the shaft seals for the stern tube are what stops the shaft tunnel from flooding. We have had one of those 'back to the future' moments, in the dark and dim past stern tube bearings were lignum vitae wood or even rubber and water lubricated. Then oil lubricated white metal bearings became the norm which gave far superior performance, massively tighter alignment and which if properly lubricated would last the life of the ship with no maintenance beyond periodic wear checks and seal renewals.

 

The change back to water lubrication is primarily environmental, as it eliminates oil releases. White metal stern tubes have outer seals but over time they can degrade, depending on draft and system design that means water coming in or oil going out. Engineers used to make ourselves unpopular by banning fishing over the side as one of the common causes of shaft seal damage for the main propeller and bow/stern thruster seals is fishing lines getting wrapped around the shaft. There was a horrible oil called Vickers Hydrox which was formulated to operate as an emulsion with massive levels of water content for things like stern tubes with damaged seals to try and avoid premature drydocking.

 

Some azipod manufacturers claim they eliminate the stern tube, as it's a podded propulsor outside the hull but it's rather disingenuous as they still have a bearing and seal between the motor and the propeller. You could design a fully sealed system with something like a magnetic clutch of the type used for pump drives where shaft leakage is unacceptable (such as especially toxic fluids) but it'd be a huge magnetic clutch and on balance every time it's looked at the potential problems make managing the shaft seal and shaft alignment trivial.

 

The shaft -sterntube alignment is one of those bits of building a ship that really does demand a lot of skill, and where experience comes into it's own, as it involves engines weighting several hundred tons or over a thousand tons, multiple intermediate bearings for a long shaft and the stern penetration on one of the most overbuilt parts of the ship. And it has to be right, it's one of those things if not right the problems are immense and trying to cure them hideously expensive. The guys that are good at it are one of those few categories of people where I would watch them in action and think 'that's impressive' as whereas most jobs I look at and consider it to be a matter of education and training, there are some jobs where the skill demanded really is difficult ti imagine picking up. Something that shocks a lot of tech types and instrumentation sales people is a lot of the best guys in Korea, Japan and China still use piano wire and mechanical instruments rather than lasers as they insist they can work faster that way. And despite scepticism from 'experts' they do it to the required tolerance extremely quickly.

 

The shaft is a sort of microcosm of the problems of trying to build ships in the UK, US, Europe. The Korean and Chinese guys are doing an alignment job pretty much on a weekly basis and are extremely good at it, the yards in the UK, US etc do it every few years and as often as not it's the first time for those doing it, with predictable results.

 

Crikey, this is a long one, I'd better stop, sorry.

 

No problem! I have an idea about a sort of inboard/outboard where the prop is driven by a poly-phase hydraulic connection rather than a mechanical shaft. The final prop unit could be serviced independently of the hull. It's just an idea.

[DenysW]

1 hour ago, Flying Fox 34F said:

Apparently, it is very straightforward to show an Organisation to be in Profit or Deficit, from the same set of figures????

I'd say the opposite is true. It's almost impossible for outsiders to dis-prove claims of profit or loss by just re-working the books. And that's why we have auditors - they are supposed to do that on behalf of the owners/shareholders.

 

Corporate Railway dishonesty (as opposed to sharp practice) was mostly about charging items to Capital that should have been charged to Revenue. It sounds innocent, but it means you are piling up debt for the future so that you can pay dividends right now. GWR sharp practice (in the 1840s and 1850s, I hasten to add) was to raise capital to build assets (railways), then mortgage those assets to build or buy more railways. In essence the money was being raised twice for one set of assets.

[Northmoor]

44 minutes ago, jjb1970 said:

I had a reminder of why I avoid open social media yesterday. A friend attending the same meeting made a very innocuous Linkedin post complimenting someone on a good presentation at the meeting, followed by a complete muck storm and melt down from people demanding the post be removed immediately, hitting the roof about him giving moral support to the enemy blah blah blah. My friend is an academic and less cynical than I so still sees these things as an idealist. He was properly upset, my advice to him was keep your social and professional accounts separate and to be frank I'd just not do social media in the public domain as even on private accounts things can leak and suddenly become a big issue. 

 

It's not just the obvious one of outrageous posts. I get that if you are publicly associated with an organization personal conduct in public matters so making Facebook posts calling for genocide, telling racist jokes etc are  a no no (and should be anyway on the grounds of human decency) but someone somewhere will find a reason to throw a tantrum over the most innocuous things. It's a lot easier just not to bother. Our communications director keeps badgering me to join Linkedin, FB etc and I just refuse and have told her it's not negotiable and our CEO is quite happy with that (he avoids it as much as he can too, though he does do it).

LinkedIn is the only SM I do and even then, only look at it about once a fortnight.  Too many treat it like Facebook (including overtly political posts) where they judge themselves and others by the quantity rather than quality of their connections.  I said here recently about Recruitment people being the worst offenders, while I don't connect with anyone unless I've actually worked directly with them and we could both say what the other does and is capable of.

 

While I am happy for a celebrity/politician/sports star to be pulled up for offensive SM posts they have made in the past and can reasonably be asked to explain, sometimes they seem to be at risk of having their careers ruined by clicking Like on someone else's comment - which they thought about for no more than a few seconds - ten years later.  I will never be famous (in fact the very idea is frightening) but it has crossed my mind that were I to become so, some journalist or political campaigner would almost certainly start trawling my RMWeb posts.  How many times have your itchy trigger fingers, for example, accidentally clicked Round of Applause instead of Funny?  That could easily be misinterpreted years later as cheering some controversial comment instead of being amused by something that was clearly a sarcastic joke.

[Compound2632]

9 minutes ago, DenysW said:

 GWR sharp practice (in the 1840s and 1850s, I hasten to add) was to raise capital to build assets (railways), then mortgage those assets to build or buy more railways. In essence the money was being raised twice for one set of assets.

 

Ah, but like George Hudson, they were achieving a public good much more rapidly than would otherwise have been the case, however bad their behaviour may have been from the shareholders' point of view. In the GWR's case the outcome was near bankruptcy in the 1860s; in the case of Hudson, the shareholders were more canny and heaped the blame on him, whilst themselves profiting in the long run. But in both cases the public and the economy benefited from rapid expansion of rail transport. 

Edited Wednesday at 07:41 by Compound2632

[DenysW]

5 minutes ago, Compound2632 said:

In the GWR's case the outcome was near bankruptcy in the 1860s

That's a bit harsh. The GWR never failed to pay a dividend on its Ordinary shares, although its financial misdeeds/over-optimism caught up with it in 1857, and it took a hit in the 1867 banking crisis. On the latter, not as badly as the London commuter railways, however.

 

In fact by the 1880s it seems to have recovered from its youthful indiscretions - and IKB's poor engineering choices - and become a well-run, normally-profitable railway.

[Compound2632]

4 minutes ago, DenysW said:

That's a bit harsh. The GWR never failed to pay a dividend on its Ordinary shares, although its financial misdeeds/over-optimism caught up with it in 1857, and it took a hit in the 1867 banking crisis. On the latter, not as badly as the London commuter railways, however.

 

I understood that in 1867 Daniel Gooch was at the head of a delegation of railway chairmen - including those of the Chatham and the South Eastern - who called on Lord Derby, begging for nationalisation.

[Happy Hippo]

1 hour ago, DenysW said:

GWR sharp practice (in the 1840s and 1850s, I hasten to add) was to raise capital to build assets (railways), then mortgage those assets to build or buy more railways. In essence the money was being raised twice for one set of assets.

How else were we going to afford  all the wonderful lovely copper and brass trimmings?🤣

[Happy Hippo]

When I put my 74xx back together after fitting the sound decoder and associated gubbins, it ran, and then stalled.

 

This was traced to a small bolt that had managed to travel from the workbench into the spokes of one of the wheels.

 

After removing the offending materiel, the loco was running, rather jerkily.  In fact a distinct bump, once every wheel revolution.

 

I decided to strip the loco completely down to the bare chassis, and was then able to do some rolling tests.

 

The result was the wheel that had been jammed, was slightly out of quarter.

 

It's a lot better now, and I'm just taking a break from reassembling the the whole thing.

 

Typically a number of the 30AWG wire that connects motor and pick ups to the pcb have detached themselves:  They are a bit short if truth be told.  So I've taken the opportunity to extend them whilst the loco is in bits.

 

Whilst I'm in the mood, I may well have a bash at wiring up the lights on the Sulzer, although my brain may be too frazzled to do that this afternoon.

 

Here is a nice surprise for those of a Midland persuasion:  Pity it's in 4mm scale.

 

https://railsofsheffield.com/blogs/news/rapido-announce-midland-483-class-4-4-0-in-oo-gauge

 

Edited Wednesday at 12:47 by Happy Hippo

[DenysW]

5 hours ago, Compound2632 said:

begging for nationalisation.

Possibly of the Bank of England? At that point it was a private, for-profit, unlimited liability company. It also did not willingly accept the role of lender of last resort.

[Dave Hunt]

1 hour ago, Happy Hippo said:

When I put my 74xx back together after fitting the sound decoder and associated gubbins, it ran, and then stalled.

 

This was traced to a small bolt that had managed to travel from the workbench into the spokes of one of the wheels.

 

After removing the offending materiel, the loco was running, rather jerkily.  In fact a distinct bump, once every wheel revolution.

 

I decided to strip the loco completely down to the bare chassis, and was then able to do some rolling tests.

 

The result was the wheel that had been jammed, was slightly out of quarter.

 

 

No wonder - it had been screwed.

 

Dave

 

Hat. coat etc. 😋

[iL Dottore]

2 hours ago, Happy Hippo said:

Here is a nice surprise for those of a Midland persuasion:  Pity it's in 4mm scale.

 

https://railsofsheffield.com/blogs/news/rapido-announce-midland-483-class-4-4-0-in-oo-gauge

 

Man,that's one fugly mutha 😁😱

 

This is an aesthetically better locomotive:

https://railsofsheffield.com/products/Bachmann-32-875a-lms-fairburn-tank-2245-lms-black-original?_pos=13&_sid=ac802bad1&_ss=r&_fid=0f4c12089

 

I also note that another obscure SR/BR EMU is being produced:

https://railsofsheffield.com/products/bulleid-class-4dd-double-decker-4002-4902-br-green-with-full-yellow-ends-dcc-fitted?_pos=9&_sid=b53772248&_ss=r&_fid=db8ecff0c

 

When are they going to produce something so commonly used it was unremarkable like this:

 

Or this:

 

or this:

 

Notice TOTAL absence of copper clad chimneys! (I can think beyond the GWR trope)

[J. S. Bach]

9 hours ago, jjb1970 said:

 ...snip... There was a horrible oil called Vickers Hydrox  ...snip...

Sunshine Bakeries made a cookie called Hydrox.

 

It turns out that they are still made but by Leaf Brands"

https://en.wikipedia.org/wiki/Hydrox

[Tony_S]

16 minutes ago, J. S. Bach said:

Sunshine Bakeries made a cookie called Hydrox.

 

It turns out that they are still made but by Leaf Brands"

https://en.wikipedia.org/wiki/Hydrox

When I looked at the photo in the article, I thought surely that is an Oreo but the text explained all. 

[Dave Hunt]

46 minutes ago, iL Dottore said:

Man,that's one fugly mutha 😁😱

 

This is an aesthetically better locomotive:

https://railsofsheffield.com/products/Bachmann-32-875a-lms-fairburn-tank-2245-lms-black-original?_pos=13&_sid=ac802bad1&_ss=r&_fid=0f4c12089

 

It's the rarefied atmosphere up in the Alps and all those cow bells. It affects the higher functions of the brain you know.

 

Dave

[Dave Hunt]

7 minutes ago, Tony_S said:

When I looked at the photo in the article, I thought surely that is an Oreo but the text explained all. 

 

My work colleagues in America tried in vain to get me to like Oreos with my morning coffee. I used to smuggle in packets of McVities dark chocolate digestives instead - less sickly sweet and gooey.

 

Dave

[AndyID]

3 hours ago, iL Dottore said:

Man,that's one fugly mutha 😁😱

 

This is an aesthetically better locomotive:

https://railsofsheffield.com/products/Bachmann-32-875a-lms-fairburn-tank-2245-lms-black-original?_pos=13&_sid=ac802bad1&_ss=r&_fid=0f4c12089

 

I also note that another obscure SR/BR EMU is being produced:

https://railsofsheffield.com/products/bulleid-class-4dd-double-decker-4002-4902-br-green-with-full-yellow-ends-dcc-fitted?_pos=9&_sid=b53772248&_ss=r&_fid=db8ecff0c

 

When are they going to produce something so commonly used it was unremarkable like this:

 

Or this:

 

or this:

 

Notice TOTAL absence of copper clad chimneys! (I can think beyond the GWR trope)

 

I prefer the class 303 (in original form and livery)

 

www.stephenjohnsonrailways.co.uk

[Happy Hippo]

3 hours ago, Dave Hunt said:

 

My work colleagues in America tried in vain to get me to like Oreos with my morning coffee. I used to smuggle in packets of McVities dark chocolate digestives instead - less sickly sweet and gooey.

 

Dave

Dark Chocolate Ginger cookies are better.

 

You'd have turned them into drooling sycophants if you'd fed them Bara Brith.

[Chris Snowdon]

11 hours ago, Compound2632 said:

 

Ah, but like George Hudson, they were achieving a public good much more rapidly than would otherwise have been the case, however bad their behaviour may have been from the shareholders' point of view. In the GWR's case the outcome was near bankruptcy in the 1860s; in the case of Hudson, the shareholders were more canny and heaped the blame on him, whilst themselves profiting in the long run. But in both cases the public and the economy benefited from rapid expansion of rail transport. 

And the trick used a generation later and for almost a century was the reverse, classifying new-builds as rebuilds, to come off the current account rather than capital account.  A different public good, according to the necessity of the time, but still "creative"

[Northmoor]

4 hours ago, iL Dottore said:

When are they going to produce something so commonly used it was unremarkable

While I share the frustration at the shortage of RTR "ordinary" EMUs, the reasons why have been debated on RMWeb many times.  There are a number of reasons, including: 

1. Likely cost of a 3/4-car unit is more than most purchasers are prepared to spend on one item.
2. People will generally buy something that excites them, than something that is prototypical.
3. While many classes can look similar, there are often a huge number of variations between batches and classes so it isn't appropriate to produce one Class 305 and just sell versions of other classes with different numbers (the days of Triang producing one DMU to suit all, are long gone).  Tooling up for multiple variants would be completely uneconomic*.
4. A high proportion of Southern-set layouts are beyond the 3rd-rail area, as the commuter belt doesn't interest the builder (see #2 above).  Likewise few modellers want to model 25kV wires and so model main lines beyond the wires.
5. Unless modelling electrified branches, EMUs tend to couple into rakes to make long trains.  So you won't need one 4-car EMU, you'll need two, which brings us back to #1.

So you're probably best off tracking down a DC Kit (other mfrs are available) of the unit you want and building it yourself.  I've a Class 304 just like your photo waiting for me to build it (had it well over 20 years already) but it's well down my to-do list.

 

*The exception to this may be the later PEP-derived and Mk3 units, of which multiple classes use similar bodyshells.  That may be why in N, there is a class 313, which can be simply modified to be a 314 and potentially a 507/508.

[Chris Snowdon]

11 hours ago, DenysW said:

That's a bit harsh. The GWR never failed to pay a dividend on its Ordinary shares, although its financial misdeeds/over-optimism caught up with it in 1857, and it took a hit in the 1867 banking crisis. On the latter, not as badly as the London commuter railways, however.

 

In fact by the 1880s it seems to have recovered from its youthful indiscretions - and IKB's poor engineering choices - and become a well-run, normally-profitable railway.

I once read somewhere that if not for nationalisation, the LNER would have paid its first dividend in 1948.  I also read somewhere that but for HMT's rules, BR would have returned a £3m profit in 1992/3.  Can't recall where I read these though...

 

Anyway:  "The paradoxical position under the rule of unlimited competition, is that competition must be limited otherwise ruin will inevitably follow" - Guy Granet.