Talk:South African Class 25 4-8-4

Reference retrieval
Reference http://www.steam-in-action.com/pdf/Albie_Bester_Report.pdf (Condenser fitter Albie Bester’s reminiscences) may be unretrievable - I get 404 error with it. So here is the complete text from the PDF file, which I have saved:

Albie Bester on Class 25 Condensers
After working on and being associated with condensing engines and tenders, building a spare tender in 1963No. 3541.........class CZ, the information that only 3511 and 3451 were still in Transnet's possession was not good news to me. Seeing that no other engines are in the hands of the conservation people like Reefsteamers and others, it must be accepted that 88 of the engines which came to South Africa are either scrapped or in the hands of the scrappers, while classes 6, 7, 8 and others much older than the 25, were still standing around, while in 1973 condensers from Beaufort West were still grinding up the 65 mile grade to Biesiespoort and the 4560 foot summit-the highest point on the Cape main line.

From 1973 as they went through the workshops, the condensing gear was removed and the condensers became free exhausting like the original 50 Non Condensers. At the beginning of 1978 only 30 more 25s had to be converted. One of the 30 was not to be converted and had to stay a condenser for the railway museum. 3540, the last of the 90, was built by North British Locomotive Company, was to be renovated by Salt River Workshops but the problem of cost was the reason given for not doing the job. The British wanted to ship 3540 to England but the Authorities vetoed that move and to prevent further plans like that, gave instructions that 3540 must be scrapped.

After the announcement in 1972 that steam would be withdrawn, I came to the conclusion that there was a type of conspiracy against steam. Senior officials in our workshop who made a good living out of steam engines and got promotion, became very near to hostile to steam. Everybody knew I was a "steam man" and remarks from these higher officials in the end became so bad that it was annoying. And the 25 class was a favourite discussion point. But it appeared that the conspirators were very friendly with the few electrical staff already present and obviously to be first in line for promotion on the electrical side.

The smoke and char problem was a famous discussion point amongst the anti steam faction. The Engineer Wardale who did modifications on the 25NC 3450 tackled the smokebox problems first. He maintained that incomplete combustion was the cause of the so called black smoke and provided 3 large holes in the side of the firebox on both sides. Friend from De Aar told me that after a trip from De Aar to Kimberley and back they only gathered a handful of char in the smokebox.

On the 25s the trouble was “solved" by extending the smokebox to catch more char which was raked out before every trip through a special hole which was covered with a lid.

To my mind no effort was made to examine the coal delivered to the Loco sheds. At Upington every fireman had a 4lbs. hammer to break the big chunks before he shovelled it in the firebox. I noticed that some of these chunks lying on the coal stage were oozing something like tar when lying in the sun for a long time.

C.P.Lewis and A.A. Jorgenson in THE GRATE STEAM TREK have the following to say about smoke." Many pollution-conscious laymen will look in horror at the almost volcanic eruptions from locomotive smokestacks. We ask them to bear in mind that these clouds consist mostly of harmless steam and particulate matter and are not nearly as toxic as the lead laden fumes coughed into atmosphere by the thousands of cars in the cities.

It will be interesting to know how much led laden fumes from diesel locomotives compare to that of the steam engines."

When the 25 classes came to the shops for heavy general repairs I was the first fitter to go on condensing tenders. I had absolutely no experience on these tenders and my supervisor was in the same position. We knew what had to be done but except for the stands the tender was put on, we had no stores items for spares etc.etc.

If you climb through the two doors at the back of the superstructure you have a good view of what went for what and where you must begin taking off. First the five large cooler fan grids had to come off. After draining the oil system of the turbine oil all piping had to be removed. And dirty was an understatement. Turbine oil is a thin oil and become very thin when warm. After such a long time in traffic, oil was inclined to find its way through seals of which there were a good number. You never managed to get all the oil from the pipes you take off and this plus that which was leaking made a pretty mess when mixed with char and ash. It must be borne in mind that the 5 fans were drawing air from outside through the radiators and mixed with that was soot, char and what goes with it.

My unskilled labourer was a "dronkie" by trade but he never moaned about dirt and would creep in anywhere to loosen nuts etc. As long as I filled in the charge forms for A W O L and other things he got into.

I had decent and expensive tools. My tools were always clean and everything in place. On my workbench I had a 3/4" steel plate. That was sandpapered and oiled in his idle moments.

With the fan grids off, the fans were drawn from the gearboxes. The gearboxes were coupled to the turbine by means of long shafts so the turbine came off with the gearboxes.

All this went to the turbine shop which was in operation for some time to repair turbines, gearboxes and pumps. After that you loosen the radiators. 24 bolts at the bottom, 24 bolts at the top. To take the radiators off was tricky. They were heavy and about 6ft. high. When the radiators were off the "roof" of the superstructure could be taken off for the boilermaker who usually had a lot of plating work to do.

By this time, you and your labourer took off a fair amount of dirt with your hands, face and overalls. Now the paint shop cleaning squad arrived and washed down the whole tender as far as stripped of items which must go to other shops for repairs. Once they are finished our shop cleaning gang arrive with shovels and wheelbarrows to clean up around the tender.

Usually the instructions to be done arrived before the tender arrived. Sometimes a modification led to another modification so by the time the tender is ready to be coupled to the engine the list of modifications was substantial. And be rest assured, by the time the engine got to its home depot, the modifications were scrutinized and make no mistake--if not, you could expect a letter of reprimand and if serious enough an inquiry at which you could be fined.

The average time under repairs for a tender was 17 days which included weekends which we did not work. The time for the engine was the same but on average there were two fitters on an engine.

Like with everything there was a day of settlement. That was the day the engine and tender were coupled up with a drawbar. Then the 70sq.ft firebox is filled with scrap wood, coal, oily waste doctored with paraffin and a few matches. And believe me it is right here that you hear words you have never heard before. It is here where best of friends come to blows if not stopped by older men. Nerves used to play a big part. Will the water pumps work? Will the safety valves go off at the right pressure? Will this, will that?!!!

The fireman loads the firebox with scrap wood and throws bundles of burning waste all over the wood. As soon as the fire is going nicely he starts putting on coal. At about 50 lbs pressure the mechanical stoker can be used. On the elevator on the inside is a manifold with jets. Every jet has a separate valve. Left Back, Right Back, Left Front, Right Front, Fine Coal. Take a shovel about half full. Open the jets as you want and let the coal slowly slide off the shovel onto the manifold. Your coal spreads evenly on the fire. If one jet is blowing too much coal, set the valve in the cab. With little effort you soon get steam BUT watch your gauge glasses. It is safer to have too much water if you light up than too little.

I know of only one bloke who worked with water playing up and down inside the bottom nut. Dick (Low Water) Marsh ex Kroonstad. He said the boiler is for steam, not water!

In the steamshed the bloke on the tender works with the bloke on the engine especially in times of crisis. The worst is when you want water, the pump trips and you try the other one and that one also trips. Or the safety valve does not "pop" and the needle on the pressure gauge is moving to higher than 225 lbs. Three blokes run to two different phones to warn the safety valve expert, but he is in the toilet with the Sunday paper.

Eventually he arrives, panting, with his overall on his knees. "WATER" shouts the safety valve chap. The needle is now on 230 lbs instead of 225 lbs. The fireman opens the Right hand pump. Just a funny noise but no water. "Try the other one" no response from the pump. "Drop fire" shouts the Loco inspector. I am busy trying to get the cap off to restart the pump. Somehow the overspeed tripping piston has moved up and blocked the steam inlet. The fireman is busy raking out the fire and the loco inspector tries to help by spraying water from the outside underneath the grates. A cloud of burning hot steam comes out at the firehole door and catches the fireman full in the face. He shouts a few very ugly words and does not see me next to the front of the footstep. He throws the white hot rake out of the cab and I rather feel the heat than see the rake. The rake shoots past my head and face and only when it falls on the ground do I see how near I was to being seriously burnt. But the pump starts pumping and the water shows in the glass. The safety pops at just over 225 lbs!

The 25 condenser was a big construction with lots of pipes, screws, bolts and nuts, turbines, fan gearboxes and fans plus the rest. You can go over it and the next bloke will find something you have missed. So from the time she is under steam you start walking around the engine and tender, go inside and check once more, run the tender turbine on live steam from the manifold on the tender face plate, check water temperature in condensate tank because it is from there that the water goes to the boiler via the feed pumps and at that stage the water is still cold. Cold water in a boiler under steam is not allowed because a boiler has hundreds of rivets of all sizes which do not react kindly to sudden temperature changes.

Once the engine starts going and exhaust steam reaches the tender, the condensation of steam starts and then you must adjust the live steam to correspond with the condensate which goes into the condensate tank.

The water level in the condensate tank is controlled by a float valve which opens as soon as the water capacity drops to below 400 gallons. As soon as it is 400 gallons the valve closes automatically. Provision for any malfunction in the water supply is made by a hand operated stop cock on the fresh water tank. It is therefore important that the fireman has to keep an eye on the water level indicator. If there was no water due to a malfunction and he opened the feed pump valve, the tripping device inside the pump would prevent steam from getting to the driving mechanism of the impeller and the pump does not work. This is what caused panic in the cab because the cap on the tripping device is sealed with a lead seal an breaking of this seal by an unauthorised person was a serious error which could lead to an inquiry.

The LOCOMOTIVE SUPERINTENDENT in Cape Town once made an unscheduled visit to Beaufort West. Blackwell was no easy character. There were complaints about engines which were released to traffic with seals on the caps but no pistons in the tripping device. He collected the LOCO FOREMAN at Beaufort West and the fitter on the maintenance of pumps. Every cap the fitter took off was properly sealed but the tripping piston was gone. And after every defective pump, Blackwell's temper rose a few knots. The Dynamite train was standing in the station on the point of leaving.

Blackwell got Operating to cancel the departure of the train. Both pumps were without pistons. A friend of mine was Supervisor in the section where the pumps were overhauled. Blackwell took him with him to Beaufort West in his Caboose. He told me that when the fitter opened the second pump on the dynamite train Blackwell early went berserk. Danger was that if the pumps failed the driver would have to stop in the section and a following train could for a number of reasons not see the train in front of him and crash into the back of the dynamite train with obvious serious results.

The easiest way to get a stubborn pump to work was to take the piston out, replace the cap and seal it. Irresponsible we say. But I worked in a running shed (Upington) where one fitter on night shift was responsible for 13 engines during the night for trains leaving north and south including the Passenger train to Windhoek on which Operating wanted double header engines because the train had one coach more than the standard one. You have no supervisor to approach for advice or assistance. You and you alone are responsible. If an engine left late you had to supply a good reason. So irrespective the seriousness of the fitter's actions -there is a limit to what you can do.

Eventually we are ready to do our trial trip. The fitter on the engine and the fitter on the tender go along. The driver, a Loco inspector goes and puts on his hat and glasses. There were rumours that the old man was colour blind, which was dangerous in a colour light signal section. But he had but a few years to go and had a large family so we amongst us decided to have a look for signals too. Drivers are tested by eye testers but there is always a chance of one being missed.

From the works we had to go to the Bay Junction Signal Cabin via Paarden Eiland. We get the green light, the engine brakes are off and the reverser in 75% foregear which means that the valves admit steam to the pistons for 75% of the pistons' stroke. The rest of the piston's power comes from the expansion of the steam in the cylinder. Therefore, the piston's stroke being 28 inches, the valve will admit steam for 21inches of the stroke. The remaining 7 inches is for expansion.

So after making sure of the green light the "Old Man" opened the regulator too far to my liking because there are lots of points and cross overs and the whole concern is 32.4 meters long and for a short time you move this and that away before you get on the mainline. Now the "Old Man" has the chance many drivers envy him. He opened the regulator to near the full open sector plate and lit a cigarette. The blower turbine reacted to that by reaching a crescendo and the speedometer indicator staying lively. I am on the fireman's side and have clear view of the signals. Green light--"Driver" and you hold up the right hand index and ringfinger. Yellow light-"Driver" and you hold up the index finger.

Red light--Loud and clear "Driver RED LIGHT". Every time he acknowledges with the left hand. We went to Bellville and then went back tender first with heat from the tender getting into the cab. Back at the workshop everyone gets a note of items he must attend to and once these are checked and everybody is satisfied, the engine goes to Paarden Eiland where the boiler, fresh water tank and condensate tank are washed out. Then it is steamed and taken to its home depot.

One of the highlights in my career was the Friday I went with on a trial trip which was due to go to Hermon but was abandoned at Wellington.

The purpose of the trial trip was that the Loco Superintendent's office wanted some data and the only way was to do a trial trip with the necessary extra gauges etc., to get the information. The staff on the trip was a Driver from Paarden Eiland who originally was a main-line driver (special grade) from Touwsriver, a fireman from Paarden Eiland, an engineer from the Loco Supt. office, my supervisor and myself.

The key man was the driver, of whom I had good information from fitters coming from Touwsriver. I worked with one of them as an apprentice and he told us a few good stories about this chap. The best one was about the day he was the driver of the Blue train. Between Touwsriver and Laingsburg some of the passengers were getting scared because of speed and the guard was forced to include complaints of that with the tablets (Holders for instructions to train personnel) at intermediate stations. At Laingsburg there was doctor and a policeman on the platform. Instructions from the operating staff that the driver must be examined for being under the influence of liquor.

The Blue train left Touwsriver about 20 minutes late and was at Lainsburg nearly right on time. Doctor examined the driver and said there is nothing wrong with him. Obviously the man would have been agitated. At Beaufort West he pulled into the station just short of right time. But here were two doctors and two policemen waiting for him.

Our Engineer friend was monsieur Bertelot, a Frenchman with dustcoat and black beret at the correct French angle. He was fresh from the Ferrari factory where he worked on superchargers. He had a clipboard under the arm and shot the driver a nervous glance now and then. The driver was no chicken anymore, clean shaven with the lines of worry on his face. After all he went up North during the war as a driver and when he came back became a Special Grade driver. It was said very softly after the Blue train episode the man was a victim of bomb shock. That left my supervisor and myself.

We were all in the cab by 7am and as the hooter went the driver looked at us and opened the regulator.

It was peak hour and we went slowly as far as Bellville. I would have liked a fast run to check on moving parts getting warm but did get the opportunity later---nearly too late.

To Kraaifontein we went faster but were held by the signal to let the Trans Karoo pass.

We checked everything possible and when we came in the cab the driver was on his seat alreadylike a race horse waiting for the starting gate to go up. The Trans Karoo came and went and our driver's hand rested on the regulator handle. Through the years they get into some habits they never forget. Like hand on the regulator waiting on the guard's whistle. This time he was not waiting on the whistle but had his eyes on the signal. Monsieur Bertelot's fidgetiness started to work on my nerves. He looked here, touched there, look at the driver who was watching him with a smile.

"Green light Driver" the fireman said. The driver opened the regulator and as 3472 started to move he applied the engine brakes and opened the regulator wide open. The 8 brake blocks were not enough to hold the two 24 inch pistons back. Bertelot was going to make a note on his clipboard then he decided against it and rather looked for a place where he could get handholds for both hands. My supervisor, a very nice chap was smoking one cigarette after the other and when the lighting up in the wind made that impossible he lit the new one with the end of the previous one.

The slacks in the line caused a swaying and bucking which I enjoyed in a nervous sort of way. I have never been on an engine at that speed but very often wondered what a sensational feeling it should be and enjoyed every minute of it.

Monsieur Bertelot definitely did not share my considerate opinion as he had his hands full with the papers on the clipboard, his beret which threatened to take off and his dust coat which kept on creeping in the open space between engine and tender. The speedometer readings were fantastic. 60, 65, moving on to 70 and as the driver prepared to drift the approaching decline put his reverser from the present 45% to the 75% prescribed before drifting the speedometer stopped on 70mph.

Monsieur Bertelot leaned over toward me and whispered "Can't he go a bit slower?" I shook my head, firstly the driver had closed the regulator and the decline added the last burst to 75mph on the wide sweep towards Muldersvlei and with the driver braking slowly the speed dropped. We stopped just before the platform for another check which was not necessary because the sickening smell of melting soft grease came towards you carried on by the slight south easterly breeze.

The grease came down the side of the slidebar dripping from where the radius rod fits inside the fork end of the combination lever. Right in the middle of nowhere. We had three options. One meant running back tender first with the heat from the tender in your face.

Second, cross over to the Stellenbosch loop where we were bound to meet a goods train which could give us a "lift" to Paarden Eiland goods yard and the last, to carry on towards Wellington at reduced speed and hope for the best. If we failed in the section meant an inquiry with Bertelot giving evidence for the prosecutors.

He took out his handkerchief and started wiping sweat off his face. If he had a mirror he would have fainted. The black smoke, soot and char mixed with sweat did not have the desired effect. His whole face was smeared with this mess. The driver took soap from his scoff-box and his towel and took my supervisor and myself to a cold tap. There he showed us how to do it. Hands, arms, face and head cleaned we felt better. Bertelot also came for a wash but the mess on his face by this time became dry and he had no success. We decided to carry on. When the decision was made the Monsieur had tears in his eyes.

At Paarl we went in a siding and in the hot noon Paarl sun we tried to do some damage control. It was no use. All we needed was an Oxy-acetyline heater and bottles. The radius rod was hopelessly out of alignment and the supervisor was one of the "that’s good enough" and "60MPH nobody sees" type. When caught out he just tried to make a joke of it.

We reached Wellington with no further damage and I decided to have something to eat.

My lunch and my favourite packet of Romany creams were all melted in one mess. I had to throw it in the firebox and had an icecream for lunch. We had to run backwards to Daljosafat to get to a triangle where we could turn round. We just made it because the engine and tender was nearly 33 meters long.

From there my supervisor took my place because from there he kept his eyes on that radius rod. "What is the good of watching the thing boss?" I asked. "Bester, if that thing breaks, I want to be able to describe second by second what happened. That bloke is not going to get away with his jokes on Monday morning."

We arrived at Paarden Eiland at 6.30 pm. 11h 30m since we left that morning. Monsieur Bertelot got off on the way to Paarden Eiland and crept through a hole in the fence to get to an office and a shower before any strangers saw him. My Supervisor and I had to walk back to the workshop to clean up. I had very little time to get roadworthy because I had to catch the last train to Stellenbosch where I stayed.

My next job was when three condensing tender wreckages, rear end collisions, which came in for repairs. One after the other. My Senior Superintendent asked me one morning whether I am paying the drivers to cause these wreckages. I suppose he was joking but he was a difficult man to judge on face value. Could never make out whether he is smiling or sneering.

You can imagine what is going to happen if a train with a 25-class and 900 ton load rams into the back of a stationary train. The back engine frame is of cast steel and can take a knock. The most damage is done to footplates and smaller items.

Although the tender waterbottom (main frame) is also of cast steel, everything above that level is in the way of the back engine---usually the smokebox. The back construction of the tender, radiators and pipes halfway towards the front always took a bad knock. Most of the time you have a chain reaction. The worst to get from the wreck were the radiators, squashed and battered in all sorts of shapes. We found that the safest way to get them off was to loosen the top bolts and get a welder to cut the condensate troughs right through between that radiator and the one next to it.

Condensate troughs were the length of four radiators and it was always necessary to remove at least four radiators. In the meantime you much watch the roof structure of the tender which was a welded construction and inclined to tear the plates or the welding and as it had happened to me, break away when you take the damaged radiator away. I always had to remember that my co-pilot was not quick off the mark some mornings or even after the lunch break on payday and had a wife and children. He was fit in spite of this little bad habit but wore thick lens glasses due to bad eyesight.

Once you have this jigsaw puzzle all sorted out, the actual assessment of the damage starts. The boilermaker straightens all bent and crooked parts that must be done on the spot and the odd bits and pieces are sent to the blacksmith shop. When everything comes back, you sort out the wheat from the chaff and get as much as possible done before the Friday morning when the Senior Supt. comes around to see how far you are, because he has received a telegram from Head Office that there has been another accident. The one tender fell over on a truck with detonators and all the radiators were burnt beyond repair. Repairs must be expedited because the wreckages will be sent to Salt River Workshop and seeing that both engines are from the one depot there will be a shortage of motive power.

And to impress me he gives me the telegram to read. In red pencilPlease give anticipated date of completion. He looks at me. I look my handiwork over. "End of next week, Sir".

He shook a finger at me "I am going to hold you to that" he says and leaves. Pressure, pressure. In the end you feel like giving the man a bunch of fives. My supervisor comes from his office. He is puffing on a cigarette like a locomotive battling up a steep gradient.

"Bester, what did you tell that bloke. When will you be able to give him this tender?" "Boss I said next Friday." "The bloody bloke told me you said this Friday." "Slowly on the cigarettes boss, not good for your chest" "Yes, yes I know. I'll try. Thank you" and off he goes, puffing much better and getting the Supt’s lie off his chest. Poor bloke died of emphysema a few years after going on pension.

The next Thursday I put the tender on the bogies and was checking around when I heard the shunter's whistle. And on the siding, waiting to take this one’s place, is another wreck. Only worse than the previous one. It took the knock fair and square at the back, shoving everything a bit further forward.

I did three in succession. They kept the worst one for the last. Another senior superintendent took over in the meantime and a day or so after the last wreck left I was called to his office. After a few words he gave me a letter. "Read it" he said.

It was about a spare condensing tender to be built to replace any which were out of traffic at the depots. R90 000 had been voted in Parliament for the job and it must be started in "this financial year"

I looked at him, speechless for a moment or two. "What must I do with the letter" I asked.

"The letter must go on my file" he said holding out his hand "and you will have to do the job" Plain, simple and final.

There was a shuffling around of supervisors and my trusted boss was going to another section. The one I was supposed to fall under was one of the joke telling specimens with no backbone to stand up against superiors.

"You go in the office with Mr. X, write out all the requisitions and sub orders for parts to be made". Mr. X was not particularly happy with what I told him and neither was I to work with him because he did not have a clue about a condenser, which left me on my own with a big job like this. There was nobody to give me advice and nobody to cover me in case of problems.

I was irritable and left in the lurch after I did my best and because I did my best this lot was dumped in my lap. I had the stores item no. for the waterbottom or mainframe of the condenser because I took note of these things. I made out a requisition and sent it to the store. The storeman phoned me very indignant and wanted to know where I got this antequated number from. Two spare frames, one for the condensers and one for the non condensers were in the contract for the 25 and 25NC tenders, plus one for an engine frame. It was placed in what was at that time an area covered with grass, Port Jackson and Rooikranz trees. As the workshops expanded, soil, bricks and scrap iron were dumped there, irrespective of these large grey coloured cast steel frames. I looked at them many times when the trains passed nearby and later where they were supposed to be, wondering what was going to happen when one of these was required. I went to the store, got hold of the storeman and took him for a walk. Over loads of dumped soil, scrap iron, building rubble etc., then I noticed the front part of the condenser frame just showing above the rubble.

I took him by the arm and carefully steered his eyes in the right direction. "You see, just to the right of that Port Jackson tree and hidden below all that scrap and dirt, you see that greyish thing?"

"Yes I see it now" he said excitedly.

"Now there is your requisition, please deliver it to Shop One as soon as possible" I walked away and was quite a distance from the spot when I still heard some very ugly words coming my way.

When the frame eventually arrived in Shop One I got hold of the ganger with his gang and their pickaxes and shovels to clean away more than 10 years scrap, dirt etc. They battled there for quite some time before everything was clean and taken away with wheelbarrows.

But--the frame was loaded upside down and offloaded that way. I called our rigger to come and turn this nearly 40 tons chunk of cast steel around. We had two 50 ton cranes so Mike got to work. He first lifted the frame side on first and put it in the pit. Then he lifted the other side a bit and showed the driver to move the crane traverse towards him.

The idea was to get it upright on the one side, lift it high enough and when high enough to get out of the pit put it on the ground and by means of heavy blocks and wedges slowly lower it where my work area was. But the crane driver misjudged him and when the frame was on its side, made a slight move towards him which made this heavy load tip over towards the side of the shop and in the process ran away with the traverse at great speed towards the side of the shop to a great calamity and plenty inquiries. The crane driver did some fancy crane driving and only just prevented what we all feared.

Mike left for a swallow or two from his half jack, I went for a cup of tea and the crane driver came down from the crane in a great hurry and disappeared towards the toilets. The ganger had to get his labourers together because the other side also had to be cleaned and they all left the place in a big hurry when it looked as if the crane traverse was going to go through the side of the shop. Perfect start you will say.

When the tenders were shipped to South Africa the radiators and superstructure of the roof was all in place. All we had to do to get them to Salt River was to put them on the bogies. For that we used the floating crane. There is not much play between the pivot on the tender and the "pot" on the bogie where the pivot must go into. There were no pits and you had to sit on the quayside trying to position the bogie when the floating crane lowered the tender. But the floating crane depends on the swells and tides. In the end it proved to be more luck than skill to get all 90 tenders to Salt River in one piece. The rest of the tender was packed in crates and boxes. Every bolt, nut and screw. I had to start with about 40 tons

The 25 condenser was not such a useless article as made out by many. For her size she gave you a nice ride and not the bone-shattering rides some other engines give you. The four wheel trailing bogie rockers with the engine weight on them give an easy rolling effect when going over points. A locomotive is expected to give smoke and one just wonders if all were done to rectify the turbine blower fan troubles or whether it was given up or even decided that it worked well enough. For 20 years they tackled the arid rugged Karoo from Touwsriver to Beaufort West and then the 65 mile last lap to the summit of the Cape Main line on the 1 in 80 climb to Biesiespoort at 4560 ft. Then westward into the Kalahari from Kimberley to Postmasburg, Hotazel and Sishen to bring iron and manganese ore which had to be shipped from Port Elizabeth. This line became one of the biggest money spinners for the SAR.

After that they were relieved of their condensing gear which had enabled them to use their own water 8 times over and a 90% water saving. When they were relieved of the condensing gear they became just one of the other well spoken of 25NC engines. 3481 had her last overhaul at Salt River in 1986 so they gave more than 31 years hard work about 2 years less than the 25NC.

88 - 25 class locomotives were scrapped as condensers and converted to 25NC's leaving us wide open for serious troubles if the water position deteriorated on the Cape Main line or other drought-stricken areas if alternate hauling power like electric or diesel was not available. Our electric position is critical and we are just about hanging on. It will only ease by 2012 to 2014.

Content of email by Dr Raimund Loubser concerning the Class 25
Original Message From: "Raimund Loubser" To: "R Dickson" Sent: Sunday, September 16, 2012 7:44 PM Subject: Re: Class 25

Dear Rollo,

Nice to hear from you. Yes, Charlie has got a few things mixed up. May I suggest that the section you extracted be based on what I submit now. It is perhaps in too much detail, and could be shortened if required, but at least it explains how my Henschel visit fits together. I am sorry, but I have no recollection of the dinner with Charlie - old age creeping up! It could have been while my discussion with Roosen and Hany was still under way and Roosen was not yet prepared to accept my findings and what it involved. I agree I was involved, but I was without a 'Dr' at that time, and never the Head of the CSIR. Let us forget my involvement with Atomic Energy and rather say 'later President of NECSA (National Engineering Council of South Africa)'. Here goes:

--- In desperation, even the National Mechanical Engineering Research Institute (NMERI) of the CSIR was consulted by the Chief Mechanical Engineer (CME) of the SAR. This was based on their successful solution to the problem by early 1956 of several failed connecting rods of the Cls 25. Tests showed that the failures were due to concealed manufacturing errors in only12 connecting rods, and that the design by Murray Franz was good.

As the failure of the turbine blades still continued even after the breadth of the blade roots was increased from 7mm to 14mm, the NMERI was asked by the CME of the SAR to again assist them in solving the problem, as the Henschel attempt had failed. Specimens of failed and new blades of both sizes were submitted and fatigue tested and stress analised. Raimund Loubser, Head of the Strength of Materials Division, could show that both sizes of blades had failed due to fatigue at the sharp fillets, under repeated changes in the centrifugal load (variations in the turbine rotational speed). This Aug 1956 report to the CME was immediately sent to Henschel, who invited Raimund Loubser to come immediately and discuss the problem and its possible solution. It took several days of discussion under Roosen to agree on the report and to find a solution - Raimund had not made a specific suggestion in the report. Henschel's Chief Engineer Hany pointed out after a few days that  the 'lock' blade, the only one per rotor, was supported by two conical pins and none of these blades had ever failed. Hany's suggestion was that these conical pins should also be introduced between all the blades in the rotor. Raimund made a quick stress analysis and supported the suggestion. A few specimens with the conical pin supports suitable for fatigue tests were then made by Henschel, and taken to the NMERI by Raimund. Fatigue tests showed that this made them considerably stronger. The design was amended accordingly and the problem was solved. Some time later, Welder Joe Walden of the SAR, welded the blades onto the rotor edge and this proved to be a good cheaper alternative.

Please let me know what is the final suggestion.

Regards     Raimund Loubser.

Posted for reference purposes. André Kritzinger 22:42, 3 December 2012 (UTC)