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

Some time with / sometime without Lined/ unlined, Early crest/ late crest, Cabside Yellow stripe ... the mouthwatering possibilities are ... endless.

 

Yellow stripe was an error. One of the batch scrapped at Darlington still had an early crest on its tender. How about a chime whistle or a little standard one.

 

Quick question. Was the boiler barrel on these the same diameter/design in part as the Crosti 9Fs?

 

Already got one in store I understand. Not sure if it is a chime or not, sure it is discussed earlier in this thread

 

An interesting question, will look it up.

 

Cylinder pattern making https://www.theclanproject.org/Clan_News.php

 

A wooden pattern - anyone know why/if they considered the polystyrene patterns as used by other groups?

Nowt wrong with a wooden one as its the traditional way and has some advantages (like been able to use it again and again), just wondering what made them go that route.

 

The pattern maker is a project supporter who is doing this part gratis...

 

Any idea if this pattern maker will be doing more for the clan? If so that's a fantastic person to have onboard, especially to reduce the costs

 

Off the top of my head am not aware of any; having said that apart from the wheels, trailing truck frame, bogie centre and Chimney there isn't much left to do in terms of large castings...
and most of these would be too big for his workshop. Its also been found that foundries and pattern makers have to be familiar with each other for things to run smoothly so that is also a factor...

 

Dont have any dims for a crosti boiler but wouldnt have thought so:
The Smokebox diameter of the Clan is the same as the Regular 9f,
The forward (Parallel) barrel section of a Clan boiler is smaller than the 9f ( which is the same diameter as a Brit) but only by inches,
The Rear ( cone Section) is the same diameter for a Clan/ Regular 9f, at the firebox end and the same taper. The Reg 9f is truncated to match the larger diameter forward section and therefore shorter.

We did have a look at buying a 9F and modifying its boiler to fit the Clan, Initially it would require a new forward section and new inner and outer firebox from the centre line down ( about the same amount of work for the conversion of County of Glamorgan) but with the redesign, uncertain steaming properties and limited life span of the 'original ' parts, plus the cost of storage / dismantling of the donor Loco/ bad will generated by cannibalising an original ( albeit a barry wreck) item the idea was rejected.

 

The smokebox diameter of a Clan is 3/4" smaller than a 9F.
With regards to the boilers, disregarding any dimensional differences, you are forgetting one important point. The boiler barrels on the Brits, Clans and Std Class 5s were made from high tensile steel. The barrels on the 9Fs were normal boiler plate. This means that the plate thicknesses are different.

 

Are we getting another chimney made? Is this to suit the re-designed draughting?
Would it be a new or altered pattern this time?
I wonder if the other chimney is being auctioned off to pay for the new one?

 

Just assumed that as it was cast some time ago without taking into account the reduced height and correct taper that its redundant...pattern probably too.

 

Sorry about absence. The automatic post notification feature seems to have stopped working. I wondered why the debate had stopped

1. Bogie parts starting to arrive. https://www.theclanproject.org/Clan_News.php. Undergoing inspection at CTL Seal

2. Chimney. Yes we will need a redesigned chimney and it is to accomodate the Lempor exhaust. You can read about it here https://www.theclanproject.org/design/Clan_Design_Clip.php

3. Yes, Tony Dance our pattern maker is interested in doing other jobs for the project. We will be visiting him in April and will be discussing the driving wheel patterns. I'll ask him about polystyrene patterns

4. Some intesting evidence as come to light on the Ferobestos pads used on the bogie bolster system (see discussion above). E.S. Cox presented a paper on "British Standard Locomotives" to the Institute of Mechanical engineers in 1951. In the paper he said "vertical weight is carried on side bearing pads, of bronze working on " Ferobestos " in lubricated condition.". In answers to question posed by the audience, he says "Ferrobestos pads on bogies are lubricated to avoid too much friction. Under certain conditions dry material
can lock the wheelbase and spread the road in shed yards."

We hope to start actual frame assembly very shortly. A number of small jobs have to come to light which need to be done before we can start. However, the list is steadily shrinking

 

Polystyrene patterns can only be used once as the pattern is evaporated when the metal is poured. https://en.wikipedia.org/wiki/Evaporative-pattern_casting. Our experience has shown that for one-off casting, the sand printing system we used for the Exhaust Steam Manifold provides an excellent quality casting. Providing quotations are cost effective, we intend to use sand printing for these castings. For the cylinders, the pattern needs to be reused for both cylinders so the traditional method has been chosen

 

Of interest ... how are polystyrene patterns actually produced?

 

There's some videos on Youtube if you search for evaporative pattern casting. One video shows the pattern being formed with a CNC router

 

The patterns for the cylinders for Project 27 were made from a series of slices of polystyrene varying between about one and two inches thick. Those were carved directly from the CAD drawings using a multi-axis milling machine, then stuck together in order to form the whole pattern.

A couple of photos:





(From https://wainrightsfinestsecr27.blogspot.com/)

Tom

 

How did you find the quality of the castings? CTL Seal said that the quality of the casting for the Exhaust Steam Spider was excellent.