Brighton Atlantic: 32424 Beachy Head

Is it possible that the load limit might be increased in the future? I understand Ivatt Atlantic 4404 hauled a 585 ton train at an average of more than 60 mph between Barkston and Selby. I know the gradients on the Bluebell are much steeper than the ECML but it does hint at what Beachy Head could achieve. Is adhesion the limiting factor?

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Something to take into account would be the much lower speed permissible on the Bluebell, which would limit the aiding effect of momentum at the bottom of a gradient when climbing. I am sure that the Railway will have chosen the weight limit wisely.

 

I appreciate why a conservative load limit for 32424 has been stipulated.

There are at least three detailed logs of Grantham standby Ivatt Atlantics taking on 500 ton plus
trains and working these to schedule as far as York ( particularly on the 1.20pm ex Kings Cross)

As with many classes of locos the H1 and H2 4-4-2s, as they were replaced by more powerful
locos, when called upon to deputise produced performances superior to anything previously
recorded. Post the 1923 grouping the 4-4-2s consistently kept the 60minutes London Brighton
non stop schedules with 360 ton trains. After the introduction of the King Arthur 4-6-0s the
4-4-2s on occasion stood in for the KAs and kept time with 450 tons. But by all accounts they
had to be worked hard. ( There is record from a Brighton apprentice who noted 40% cut off
continuously Brighton to Victoria. ROs were four fifths up hill, two fifths down. load 450 tons )

The following page indicates how the H2s were working in the 1953/4 period.

There are also records of Atlantics hauling 9/10 coach trains between EG and HK. I appreciate
that post the clearance of the Imberhorne rubbish heap there is now a short 1/55 stretch.






Michael Rowe

 

I doubt it would change.

Doing a bit of fag packet maths, the combination of decreased boiler pressure and increased ruling gradient makes a big difference relative to an Atlantic running over the Bluebell in the 1950s.

I put a photo up earlier of Trevose Head on an 8 coach train back in 1955 on Freshfield Bank. If we assume those coaches were about 32 tons each (typical for Maunsells) then the gravitational pull for a combined 365 ton train (including 109 tons of loco) on a 1 in 75 gradient is about 10,900lbs. You have 24,500lbs of nominal tractive effort, so the loco is using 44% of its nominal TE to overcome the gradient. (To which you then add other resistive forces; and of course the reduction in TE at speed, until all the forces balance and you achieve a constant speed).

Do the same maths but increase the gradient to 1 in 55 and cut the boiler pressure to 170psi (and therefore nominal TE to 20,800lbs) and the same train needs 71% of the loco’s TE to get up the 1 in 55. That’s beyond what we would push anything to. Even with the load cut back to 185 tons, you need 57% of the available TE to get up the 1 in 55 section, i.e. working our loco at its load limit would, for 1/2 mile at least, require it to be working closer to its limit at a given speed than Trevose Head was back in 1955.

The gradients make a big difference. In comparison, I don’t think there was anything steeper than 1 in 264 between London and Brighton, except the initial pull out of Victoria where I believe a banker could be used.

Nonetheless, it would be really interesting to know in detail how the locos were fired over long distances, given what we are finding - particularly how - or even if - firemen of the day fired to the back corners without opening the whole fire hole door. Maybe those with modern-day experience on LNER Pacifics might have some insight.

Tom

 

As part of our testing of new locos (including types that haven’t previously run to East Grinstead, such as Fenchurch when it appeared in 2022, and hopefully the Adams Radial and Normandy in due course) we always carry out a test of whether they can restart the proposed load limit from stationary on the 1 in 55. So rushing the banks isn’t an option, you have to be able to start on them and generally hit all but one of the major banks from either a stand, or (in the case of Freshfield Bank) a low speed restriction.

Going northbound, Sheffield Park is really the only easy start. Both Horsted Keynes and Kingscote start climbing pretty much from the platform ramp. The Horsted Keynes up inner home is another place where it is not uncommon to be stopped and require a restart on a gradient, at that point 1 in 75.

Tom

 

Tractive effort values are the result of an arbitrary formula. If you reduce the coupled
wheel diameter for instance the TE increases. The actual tractive effort is at a maximum
at the point of first movement and decreases there after.

The question then arises wrt gradients “Do you set the load on the basis of restarting on the
gradient or do you allow for the speed at the start “ i.e allow for loss in kinetic energy.

Under BR jurisdiction loads ( from memory ) were set for leaving Weymouth and climbing
the 1/50 , 1/52 between Upwey and Bincome at WC/BB 287 tons, GWR Castle 310 tons.
My understanding is these figures reflected adhesion ratios plus Class idiosyncrasies. In
practice either Class of loco, even with the cranks in the most favourable position, would have
struggled to restart ( particularly if within the tunnel ) with these loads. Maunsell Moguls
were allowe 255 tons ( from memory ! ) always regarded as similar to the H1/H2 wrt loadings.

To sustain 20mph on 1/55 with a total train weight ( loco plus consist ) of 350 tons would
require c. 850 EDHP. If speed fell from 20 to 15 mph over half a mile at 1/55 then
c 575 EDHP. H1/H2 in their 200psi form produced 900-1000EDHP regularly.

In summary whilst I think starting 32424 on 1/55 with eight coaches might be a challenge
actually surmounting said Gradient not so challenging.

Michael Rowe

 

Tom, you might like to try to get hold of a copy of "On engines in Britain and France" by Pat Ransome-Wallis, published by Ian Allan in 1957. Chapter 10 Part II gives a very detailed account of a return journey from Brighton to Bournemouth in early October 1955. The loco was 32421 "South Foreland" with a load of 8 bogies for 262.5/290 tons. I've not read it in detail recently but I'm sure that you will find P R-W's observation on the working of the loco facinating. At one point he comments on the fireman's struggle with a dirty and clinkered fire on the return trip. With pressure down to 150lbs "half regulator and 35-30 per cent cut-off were now the order of the day" on the approach to Worthing but speed was generally higher than on the outward leg along this strech. He says "It was almost as if the engine ran more freely with less regulator and a lower pressure"

The whole book gives a facinating insight into the operation of steam in the UK in the 1950s

Peter

 

Most of the Brighton line does have a 1/264 ruling gradient ( 20 feet per mile ) but the initial stages
Victoria or London Bridge to East Croydon are more challenging.

After the 1/64 up to Grosvenor Bridge from Victoria the two miles from Clapham Junction are at
1/166 with 1/99 from Wandsworth to Balham Junction then rising to Selhurst at between 1/264
and 1/100.

From London Bridge there are 2.5 miles at 1/100 from New Cross Gate to Forest Hill.

The Brighton 60 minute trains would have taken the Quarry route avoiding Redhill. An
initial 1/100 1/125 after Coulsdon North, to gain height over the Redhill line and then
1.5 miles at 1/166 up to Star Lane Box and the tunnel entrance. ( Quarry summit )

The UP direction was arguably easier with only the 3.5 miles from Earlswood to
Quarry Summit being steeper. 1/163, 1/200, 1/230, 1/206.

Working 450ton trains over the 51 miles in 60 minutes with major speed restrictions
at Clapham Junction and East Croydon and 60 mph limit at Earlswood was I suggest no
sinecure with a King Arthur or Baltic tank and definitely challenging with an Atlantic.

An interesting working post WW11 was the 6.10pm Victoria to Uckfield and Brighton with
an East Grinstead portion detached at East Croydon ( post 1958 when a WC/BB was
rostered Oxted ). There are records with H2s and “ten on” ,350tons gross, keeping the
17 minutes schedule. Rear end assistance, if any would have only been to platform end at
Victoria. ( similar to procedure at Waterloo )

Michael Rowe.

ps The Ransome Wallis book is I agree interesting. When it was written it was suggested
the handling of the 4-4-2 was not as good as on other occasions. The 1952 RCTS
Victoria Brighton 60 minute workings with eight Pullmans were a better indication
perhaps

 

https://www.bbc.co.uk/news/articles/ckgwqz6005do.amp

BBC coverage of The Brighton Atlantic.

 

Hi Michael, I find your comment very interesting but I come at it from a very different angle. To me the interest in Ramsome-Wallis book is not that it records heroic record breaking performances by a few very keen drivers but rather he retells what life was like on often very indifferent engines manned by run of the mill enginemen. I know that the performance fraternity love to show what can be achieved in ideal circumstances but day-to-day railway operations are about much more than that. To me a good engine was not one that can go from A to B faster than is normal but one that can do the job asked of it despite the adverse conditions that prevailed in post war Britain. In this respect P R-W records 32421 as a capable engine in the hands of an average but very able pair of engineman who did the job that was required if them. What more can you ask?

Peter

 

Meanwhile ... this average engineman is thinking about 170 tons on a non-stop run culminating with a 1 in 55 bank on a largely unfamiliar engine on Monday <eek/>

Tom

 

Good luck with that Tom - I might just be there to see how you get on.

Peter

 

No pressure then! The working notes say the loco is due to stand for a period in platform 1 during the run round to allow cab visits, so say hello if you are around.

Tom

 

Send it!

 

Thanks, I agree entirely with your sentiments wrt “day to day operations”. Ransome Wallis’s book is I
think particularly interesting as his visits to the footplate do not appear to have been orchestrated in any
way and therefore reflect day to day performance,

As an aside ;Over the 1963-7 period I travelled 30 times on the
non stop 08.30 Waterloo to Southampton. Although much of the intermediate running was ‘spirited’
we never actually arrived in Southampton on time.

I was trying not to be an armchair critic when I made the comment re the handling of 32421.
PR-W p.188 ) wrote ;

“The fire got more and more dirty and clinkered and the coal dust got less and less like coal. Bolingbroke
worked continuously with fire irons and shovel, but it was seldom possible to use full regulator and
there was seldom more than 150 lb of steam on the gauge. So half regulator and 35-40 per cent
cut-off were now the order of the day. The extraordinary thing is that speed along the gently
undulating track from Farmington Junction to Worthing was generally much higher on this
journey than it had been going outwards with good coal, plenty of steam and the same load.”

On the outward journey controls had been RFO and 30%. As I understand it neither the Ivatt
or the Marsh derivatives were driven on Full Regulator. 40% cut offs with Regulator adjustments
from two fifths to four fifths being the norm. The Driver’s comment to PRW that “ the engine
needed more lead on the valves” on the outward journey is perhaps relevant.

But then it’s easy from my arm chair.

Michael Rowe

 

BBC coverage.

https://www.facebook.com/video.php?v=2338193853054842

Tom

 

Latest news from the Bluebell Railway. <BJ>

''We've had a brilliant first day with 'Beachy Head' entering service on The Bluebell Railway.
Make sure you join us this weekend for our 'Brighton Works' event between tomorrow and Monday during the bank holiday. Don't forget that 32424 will be running every day until Sunday 1st September.

Here we see 'Beachy Head' powering away from Horsted Keynes on its very first public passenger train''.

 

We were intending on visiting the Brighton works event tomorrow but the weather forecast is pretty grim for most of the day with stormy conditions. I hope everything goes ok tomorrow. We will now visit on Sunday or Monday.

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Some more nice coverage and filming from today:

https://www.itv.com/news/meridian/2...team-train-begins-working-the-rails-in-sussex

Tom