BR Standard class 6 No. 72010 'Hengist' and Clan Discussion Thread

Surely the spencer moulton washers on the rear tender drawhook go some way to providing a damper arrangement.

 

Germany had a general rule that 5 rps was max for 2 cylinder simples and 6 rps for 3 or 4 cylindered and that the maximum hammerblow per wheel should not ecceed 15% of stationary wheel load.PostWW2 DB baureihe 66 was allowed to cheat a little and pulled train very even.Max RPS was allowed 5.5 rps with 1600mm wheels that is 100kmh.
But only on rails that allowed 20 tons per axle.That means that it was allowed 23 t0ns max stationary plus blow. BR 66 had a max axle load of 16 tons. Hammerblow amplitude could thus be 14 tons per axle.Multiplied by 3 that makes room for almost 42 tons reprocicating balance at 5.5 rps.
I have no information how much was applied but surely more than 60% and then fore and aft surging was not a problem.And yawing not either

 

The Flying Hamburger diesel in the thirties got a lot of publicity and was really fast on the level .
The steam believers tried to compete with two cylinder pacifics BR03 but gave up when more than 120kmh was demanded.
And made it a threecylinder accepting that steam consumption was 4-7% higher.
Same story in Sweden.
Latest passenger lokomotive SJ E10 was built 1947 ,three cylindered and 1400mm drivers.Was permitted 70kmh but could and did run faster.
The Norwegian fourcylinder compound Dovregubben had 1540mm drivers and did solidly better than the German two cylinder 01 Pacific at 100 kmh.
The German Pendant to COX,RiddlesUrie.etc (two cylindr outside simples are all we need) was Mr Nordman.
He was very surprised that the Dovregubben had no rubber,damper,springs etc between locomotive,tender and train as all german twocylinders needed.

 

The ultimate small wheeled ,fast two cylinder locomotive worked very hard for 35 years around Paris.
https://gallica.bnf.fr/ark:/12148/bpt6k6482666t.r=?rk=21459;2

The civil accepted 22tons per driver axle with no hammerblow.
CME was mr Caso and he selected a valve gear invented by a mr Cossart.
There is a counter conrod for valve drive and that neutralises more than half of the fore and aft movements

The speed with 485 tons going 5 promille up over 30 km can be seen page 221 on the above source.
110 kmh with 1600 mm drivers is 6 rps push-pull.

https://www.mylargescale.com/attachments/la-141-tc-nord-20-jpg.46450/



Hengist can be tamed same way that is having one crank throw on front or midle drive axle and put a conrod like thing on with an owerweigth little end.Will not disturb the purist and will prolong life of loco.The extra mass on little end of balancing rod can be adjustable and taken of for less than 25mph dutyes

 

In 1924/25 tests were carried out on two equivalent 2-8-0 designs, one was a two cylinder type the other three cylinder and the three cylinder engine showed significant economy over the two cylinder type in consumption per draw bar horsepower hour. The 1924 test gave coal consumption rates of 5.18 lb./dbhp hr for the two cylinder design and 4.43 lb./dbhp hr for the three cylinder with the respective water consumption rates being 29.9 lb./dbhp hr and 26.2 lb./ dbhp hr.
The 1925 results gave coal consumption 5.25 lb./ dbhp hr vs 4.79 lb./ dbhp hr and water consumption rates of 31.95 lb./ dbhp hr vs 28.15 lb./dbhp hr. These results show a very distinct advantage to the three cylinder design and we are not talking 4-7% here either. As I have written before, steam locomotives are very strange. Which is why they are both so interesting and also so frustrating.

In Feb 1923 Holcroft presented a paper at the GWR Mechanics Institute entitled The Modern Three Cylinder Locomotive, you can find it at the kesr-mic.org.uk which is Kent and East Sussex Railway's Virtual Mutual Improvement Classroom. Have a read of the paper and look through the illustration figures, the variation in tractive effort is one the variation of tractive effort and adhesion showing the effects of the balance weights is another, but if you already have this paper then apologies.

The Dovregubben was outstanding as I have commented before. The lack of damping present in the locomotive to tender coupling should come as no surprise to those who appreciate a smooth balanced power output. Pity the Germans appeared to learn nothing from their experience with the type since you do not need driving wheels 2 metres in diameter to run at 130 kmh. I would say that the S 3/6 were, on balance, the best of the German Pacifics.

 

Having seen the latest News I wonder how long the paint brushes are on this project? and then again, how do you paint a long narrow tube inside, without missing a single bit? https://www.theclanproject.org/Clan_News.php

 

Tie some string round a trained ferrett's waist ......

Seriously though .... wonderful to see things progressing steadily. I'm afraid I've lost track, what with all the to-ing and fro-ing, but has the project come up with a definitive solution for the unavailable trapezoidal section springs?

 

I think a length of trimming would be more appropriate than string..................

 

I'm curious as to there being paint in there at all. (Having seen this lot get green paint out of red paint tin before, mere impossibility won't stop them).

Assuming there are oil seals on both ends and the box is full of oil and axle, isn't it just something else to flake off and get crud in the bearings?

 

Use a pipe brush ( bog brush on a stick) to paint and a camera probe (mobile phone on a stick) to check. ...

 

One of the reasons why we chose light grey paint was to get the maximum amount of light inside. Ashley is doing a cracking job. I should have some pictures of the painted end covers on Monday.

We are getting advice from ex BR engineers who worked on Timken axleboxes and they tell us that the axles and the inside of the cannon boxes were painted

Trapezoidal section springs. Our position is that these can be fitted at any time so we are still making enquiries

 

Fascinating, is the inside of the middle generally oil-coated or not?

 

As you can see in the drawing, although there are sumps at each end of the cannon box, the oil level is above the "floor" of the cannon box tube but does not fill the cannon box



In grease lubricated cannon boxes, grease is pumped in to fill the cannon box until it appears at the axle ends - the condensing vents are blocked off. E.S. Cox had strong views on this and the meeting minutes report "Grease Lubrication of Roller Bearing Axle Boxes - in answer to a question by Mr Miller, Mr Cox said that it had been agreed to use grease for future designs but that it was left to the regions to decide whether grease can be used for existing boxes. He thought himself that it was absurd to apply grease to cannon boxes which would have to be stuffed full."

Once the engine starts moving, oil will be sprayed around the inside of the cannon box as the bearings move through the oil sumps

 

Interesting, I wonder what the rolling resistance of all the grease is? Absent of that, it seems more logical to stuff with grease.
https://www.engineersedge.com/lubrication/functional_properties_grease.htm

Suggests the drawbacks of grease are lower cooling properties and greater resistance.

From your post above, I assume the Clan is going the oil route, as per the original BR route?

 

Yes, oil lubrication - see here for an explanation

https://www.theclanproject.org/design/Clan_Axleboxes.php

 

Busy day today - lots of pictures at https://www.theclanproject.org/Clan_News.php

We're very close to sending the bogie wheelsets down to South Devon Railway Engineering for assembly

 

The kit of parts for the assembly of the bogie wheelsets arrived in Buckfastleigh last Thursday. John is liaising with SDRE as to when they will start work.

Today we started fitting the bogie bolsters to the main frames which is another fitting job - see https://www.theclanproject.org/Clan_News.php. John came away with suitably blue fingers for Halloween from applying engineers blue for most of the day. The right hand one is now ready for drilling out the mounting holes to final size and reaming. The left hand one needs more fitting work.

 

The slow, accurate, work continues each week. What will await us when we come to the AGM???
All thanks to the working team, and the donors who finance the work.

https://www.theclanproject.org/Clan_News.php

 

You aren't going to see a lot of change from last year because our prize exhibit (the bogie cannon boxes) will be down in South Devon

However, we will explain what's been going on and why it's being painstaking work

We will have the bogie frame loose assembled and, hopefully, the right way up. One of the frame plates still needs a bit more work on the frame plate to stretcher joint - thats why it will be loose assembled. You will see the very fine bogie spring cradle assemblies. We have a quote for assembly but will not send them off until after the AGM

Look forward to seeing you all!