Jump to content

Bachmann 94xx


OnTheBranchline
 Share

Recommended Posts

4 minutes ago, tomparryharry said:

Meanwhile, in a sorting office in Penarth Road, Cardiff... 

 

" has he gone? Can we come out of hiding now?  We've been cooped up with this parcel since 2017....."

 

On another note, it would appear that the gestation period for the model is fairly close to the actual service life of the real thing....

Just over 5 years.  8448 was one of the shortest serving, never overhauled or repainted and probably never cleaned during her service life.  Some of the replacement D95xx had even shorter service lives, at least with BR. 

  • Like 1
Link to post
Share on other sites

3 hours ago, Captain Kernow said:

A favourite yoga position?

 

I was thinking of another upside down pastime.........:o

 

 

 

 

 

 

Stop sniggering at the back

I meant wiring the underside of a baseboard, of course:jester:

Edited by melmerby
  • Like 1
  • Informative/Useful 1
  • Funny 2
Link to post
Share on other sites

12 hours ago, The Johnster said:

Running trials; very good, the standard I have come to expect from Bachmann.  She is noticeably more powerful than the 57xx or 8750s with the loaded minerals, perhaps even having the edge on my 56xx, so there is no detriment to the coreless motor, and the ballasting is as effective as the heft in your hand suggests.  She will of course improve even further over time, all my Bachmanns do.  At Tondu 94xx were mostly used for passenger work and she is more than competent for this, smooth stops and starts no problem.  She can run anywhere on the layout without issue.

 

Next is to attach the details, needs to be done now because they are much less likely to be lost if they are stuck to the loco.  Some photos; loco straight from box nothing done to her yet....

 

 

IMG_0774.jpg.c45ac21ee7fc9d52ff9f45f54bd88e07.jpg

 

Running in to the loop with empty stock for the 08.20 ROF Tremains workman's.  An auto for Bridgend is occupying the platform road and once it has departed, 07.55, the 94xx will run around, draw it's train back out and then propel into the platform road.

 

 

 

 

IMG_0775.jpg.8b1477d2505e78abbcb08d1ae0d08332.jpg

 

Few seconds later as the ecs grinds to a halt.  The cab floor colour is apparent in this shot.

 

 

IMG_0776.jpg.1eca8afd276a7b46bd2b8febb825eae2.jpg

 

Looks perfectly at home with the Hornby  Colletts.

 

 

IMG_0777.jpg.03253cfbd1d2e4fe575eb4a968d0e669.jpg

 

Having run around, and propelling the stock into the platform, we pause for water before the train is finally postitioned for the passengers and the doors unlocked.

 

 

 

IMG_0782.jpg.387984597a2204388f83b93f8ad24c56.jpg

 

Shot from the mountainside shows the  cab roof rivets up.  The sliding ventilator doesn't... 

 

I am as yet unaware of the firebox glow, which suits me fine.  I did notice it when the loco was upside down running in, a rather feeble red which doesn't look as though the fire is healthy at all.  Not impressed, but I might change my mind when I do some low light running.

After the video of one of them running jerkily, it’s reassuring to learn of a smooth-running model. I’m still awaiting my sound-fitted firebox-glow controlled model. Unlike Johnster, the delay is welcome due to overstretched budget.

Link to post
Share on other sites

23 hours ago, The Stationmaster said:

I remain very puzzled by this apparent fascination with firebox glow.  Anyone would think that engines ran around all the time with open firebox doors.  Taht was a long way from the truth because you only open the doors to actually fire the engine, leaving them open is a route to cold air getting onto the firebox in exactly the wrong place.  so intermittent firebox glow would make sense but no more than that.  

 

As for steam sound I'm still waiting for somebody to get it right although the Accurascale multi-speaker arrangement for the Manor does give cause for long overdue hope in that respect.

 

Several people have derided the 'firebox glow' feature on this and other recent models as a gimmick. Some have questioned how much demand for it and suggested it is merely to justify raising the RRP. I find that a strange conclusion to draw given that most reviews of this model have concluded that it is excellent value for money! The fact that it has sold out so quickly seems to suggest a very large number agree, whether they were 'statistically surveyed' or not.

 

Others have questioned it on grounds of prototype authenticity. I have enormous respect for Stationmaster Mike, one of the most authoritative contributors on RMWeb, but on this issue I disagree. I was fortunate enough to fire locomotives on over 30 occasions at a certain well-known steam railway. I've fired a 'Hall', 'Manor', large prairie and a pannier as well as some locomotive from other railways. Before you are let loose on such machines you do a considerable amount of learning, and the principle source of learning is the 1957 British Transport Commission 'Handbook for Railway Steam Locomotive Enginemen'. It explains with great clarity that the firehole door has a far greater role than merely allowing coal to be added. To explain, coal is far from being just a dumb 'black rock':-

1634406396_AVERAGECOALCONSTITUENTScopy.jpeg.8d9acbcea8dae162531a38213a60e6b1.jpeg

 

Coal has multiple components which can burn to produce heat: solids which burn on the firebox grate and gasses (hydrocarbons) which are liberated from the burning of 'volatile matter' in the coal.  The volatile gasses must undergo a separate combustion process above the fire bed if they are to produce heat and contribute to steam production. It's at this point that the firehole doors play their critical role. To get the volatiles gasses to burn airflow is needed above the firebed and it is the firehole doors, along with the so called 'flap', that the fireman uses to control that airflow:-

 

1921677454_PrimaryansSecondaryAir.jpeg.da6bdc999c11a574e0fdf44e7ef3c731.jpeg

 

So the firebox door is kept open above and beyond firing coal. The question is by how much and how often? How much the door is opened is judged by observation. Firemen are trained to continually check the exhaust coming from the chimney as it is the best way of gauging the correct door opening:-

 

1987565867_ERCENTcopy.jpeg.c479065450d91c5841420a4862edab59.jpeg

 

If the smoke from the chimney is black, the volatile gasses are passing out of the chimney un-burnt and potential heat is being wasted to the atmosphere. The fireman then opens the doors a bit more to allow more secondary air. If the exhaust is 'clear', then the doors are open too much and the fireman should close the doors a bit or maybe completely. When the exhaust is the classic 'light grey' that we all recognise, the fireman knows that the firehole doors are set correctly and will leave them as they are.

 

Moving on to 'when' the doors are opened or closed. It is true that the firehole doors must be kept close as much as possible when the loco is being worked hard, as the flow of (cold) secondary air will then hit the tube plate, cooling it and inducing stresses. The doors should also be fully closed when entering a tunnel to protect the crew from the phenomenon of 'blowback', a situation where the normal direction of the flames towards the chimney is redirected and instead the fire comes out through the firehole door into the cab. These incidents are mercifully rare but men have been mamed and killed by blowback. However, most of the time a loco is neither being worked hard nor is blowback a risk. Much of the time a train is coasting and the opening of the firehole doors depends on different considerations. For example, if the boiler pressure is at or near 'blow off' and there is not scope to cool the boiler by using the injector to introduce cold water, the firehole doors will typically be kept open to lose some unwanted heat!

 

As you can see, even something as apparently simple as the firehole doors play a complex role in the safe and efficient operation of the locomotive. It is over twenty years since I worked on steam, but my abiding memories are of that incandescent mass at your feet, just inches away. So much of your day working a locomotive depends on it. With a strong, hot, white fire a lot of your problems go away. But if your fire is weak (too thick, too thin, uneven, clinkered...) you are going to have a hard day on the footplate! A good fireman can look at his fire and read it like a book. He knows exactly how strong it is and how to maintain it. Sadly, I never reached such a level of expertise!

 

I respect the opinion of those who consider firebox glow a gimmick. They are entitled to their opinions. But for me, that orangey flickering glow is part of the visceral experience that is steam. It means the loco is 'alive'. A loco without a fire is dead! And at night time, more than any other time, it is and essential part of 'the magic'......

 

9678D601-9DE2-4401-B96B-FB8942905157_1_105_c.jpeg.96ce4e53bd9b1093122d880a42c55837.jpeg

 

B492B6DF-9685-44FE-A872-2A29015D28FE_1_105_c.jpeg.ac38bed245a11a13198bd818feeac671.jpeg

  • Like 7
  • Informative/Useful 8
  • Round of applause 3
Link to post
Share on other sites

  • RMweb Gold

Don't forget the reason for the exhaust goping black is down to over firing and resultant poor combustion - which restrics the flow of primary air through the firebed by making it too deep.

 

Yes you will get glow when the firehole door is open, yes in western engine you can fire to the flap to reduce secondary air flow when combustion rates are high but too much secondary air when an engine is working causes damage so you only open the doors to fire.  But glow. only occurs when the firehole doors are open and no engine will work continuously in that state although the doors will be opening and closing frequently when working hard and firing correctly - one hand for the shovel and one for the doors.   Just try on a boit of fairly heavy uphill work on a mainline or fast running over along distance.

 

A great illustration of the latter is the A4 on its 100mph test run on the GWML where it is seen approaching Taplow - little and often firing and minimal secondary air..

  • Informative/Useful 1
Link to post
Share on other sites

51 minutes ago, The Stationmaster said:

Don't forget the reason for the exhaust goping black is down to over firing and resultant poor combustion - which restrics the flow of primary air through the firebed by making it too deep.

 

Yes you will get glow when the firehole door is open, yes in western engine you can fire to the flap to reduce secondary air flow when combustion rates are high but too much secondary air when an engine is working causes damage so you only open the doors to fire.  But glow. only occurs when the firehole doors are open and no engine will work continuously in that state although the doors will be opening and closing frequently when working hard and firing correctly - one hand for the shovel and one for the doors.   Just try on a boit of fairly heavy uphill work on a mainline or fast running over along distance.

 

A great illustration of the latter is the A4 on its 100mph test run on the GWML where it is seen approaching Taplow - little and often firing and minimal secondary air..

I agree with you entirely Mike, but my point is that a loco with its firehole doors permanently closed is no more and no less realistic than one with the doors permanently open! I think the ideal solution here might be for manufacturers to fit a small switch to the underside of the chassis so that those on DC who don't like firebox glow can switch it off. These days I have moved over to '0' gauge where most ready-to-run models have firebox glow which is switchable on DCC. Someone posted on this thread that the firebox glow on the 94xx isn't switchable even on DCC. If so, that is an unfortunate omission......

  • Like 1
Link to post
Share on other sites

I cannot imagine that the provision of a couple of red leds in the wiring makes any discerncable difference. and £129.95 is the RRP level that Bachmann want for this loco irrespective of whether or not firebox glow is a feature.  For DC, it is effectively a freebie, and if you don't want it you can either cut the supply to the leds or paint over them.  It is certainly not something I regard as a waste of money and does not have any perceptible effect on the performance of the loco.  So stop complaining about it, please, gents (I am as guilty as anyone for bringing the subject up and must accept the blame to a degree of course).  We have learned a good deal about the role of firebox doors from Mike Stationmaster and 7007GreatWestern, but I suspect the usefulness of this part of the thread is now exhausted.

 

What we really want for DCC is of course operating firebox doors...

 

2 hours ago, No Decorum said:

After the video of one of them running jerkily, it’s reassuring to learn of a smooth-running model. I’m still awaiting my sound-fitted firebox-glow controlled model. Unlike Johnster, the delay is welcome due to overstretched bud

I suspect that the jerky running is down to some DCC glitch or maybe a tight spot in the motion or perhaps overtight keeper plate screws.  The tight spot is IMHO most likely and is fairly easily identified and dealt with or you can return the loco.  I am sure that your 94xx will be a delight; mine certainly is!

  • Like 1
Link to post
Share on other sites

36 minutes ago, The Johnster said:

 

 

What we really want for DCC is of course operating firebox doors...

!

And a fireman shovelling coal and a driver operating the regulator and a ..............

:lol:  

  • Like 1
Link to post
Share on other sites

Operating firehole doors, and reversing levers and rods, and possibly even regulators, are not impossible and a driver with flexible arms attached to the reveser and regulator might be able to appear to operate them.  A working fireman might be a bit more difficult; perhaps he could swivel his body to appear to pick up coal from the bunker or tender and then 'present' it to the firehole, where the doors would open to recieve the round then close again, frequency determined by feedback from the load, amperage, at the motor. 

 

Or, perhaps this lockdown shielding business is getting to me...

  • Like 2
  • Funny 2
Link to post
Share on other sites

1 hour ago, Danemouth said:

All joking apart one feature I would love to see are locos with remote uncoupling built in via DCC.  No more magnets ramps etc.

 

Dave

One of the problems is which coupling do you use?

Tension locks are IMHO pretty awful but could be done fairly easily as per the aftermarket idea of no hook & dropping the loop.

Likewise opening the jaw on a knuckle couple could be done, whether that would work satisfactorily with only the loco coupler in the uncouple position , I don't know.

However whichever was used would make changing to an alternative much more difficult.

 

Link to post
Share on other sites

Dismantled mine today and noticed that Bachmann have now had another change to axle sizes ( as a precursor to investigate possible P4 conversion) my micrometer gave me a size of 3.20mm which is as close to 1/8” as near dam it! The chassis also has individual axleboxes on all axles, but no springing and no  movement up or down. 
Any one else had a fiddle with the chassis?

 

David

 

  • Informative/Useful 1
Link to post
Share on other sites

1 hour ago, Danemouth said:

All joking apart one feature I would love to see are locos with remote uncoupling built in via DCC.  No more magnets ramps etc.

 

Dave

I could have sworn I saw that on the Blue Peter layout as a child.

Link to post
Share on other sites

  • RMweb Gold
39 minutes ago, Norton961 said:

Dismantled mine today and noticed that Bachmann have now had another change to axle sizes ( as a precursor to investigate possible P4 conversion) my micrometer gave me a size of 3.20mm which is as close to 1/8” as near dam it! The chassis also has individual axleboxes on all axles, but no springing and no  movement up or down. 
Any one else had a fiddle with the chassis?

I did have a look, but assumed that the axles were the standard 3mm. If they are effectively 1/8", then that gives me a route out of poor running on chaired OO track, namely to substitute the Bachmann wheels with some Markits ones.

 

Still doesn't help with the P4 conversion, in terms of the available width inside the splashers.

 

  • Friendly/supportive 1
Link to post
Share on other sites

5 hours ago, The Johnster said:

I cannot imagine that the provision of a couple of red leds in the wiring .......

I understand the DCC guys have the luxury of one red and one yellow LED - which might give a realistic combination ...... the red alone - which we DCers are stuck with - doesn't look right to me, I'm afraid.

 

2601.28 ; DSC_0141.JPG

  • Like 1
Link to post
Share on other sites

  • RMweb Gold

Running in session tonight on the roundy. Running out of coal wagons on the load test and it hasn't flinched yet, but it is starting to find out which kit built wagons need a bit more weight :lol:

 

Currently got a 50-wagon rake of assorted 7-plank, 16T, 20T and hoppers in tow.

Will I run out of track before I can overload it? Not a problem for normal running as my usual train load is about 15.

  • Like 2
Link to post
Share on other sites

  • RMweb Gold
1 hour ago, TheSignalEngineer said:

Currently got a 50-wagon rake of assorted 7-plank, 16T, 20T and hoppers in tow.

Will I run out of track before I can overload it?

Got up to 62 wagons before it refused to do the most difficult of move round the layout and through the fiddle yard. It included the full weight of the train being stretched out across a curved turnout tight side and two double slips through the back platform loop and two 24" radius turnouts in the storage loops.

Incidentally my second Dapol Mogul did the test and was able to start the same train while the first one was tested with starting a ten coach passenger train. Some of these modern locos are certainly getting decent haulage capability.

  • Like 5
  • Informative/Useful 1
Link to post
Share on other sites

  • RMweb Gold

Just to clarify my earlier post. I did indeed refer to the glow as a 'gimmick'. If the LED worked as it should, then that's ok. A lot of people reported that it sometimes doesn't. The failure to apparently work will be regarded as a 'fault; something to detract attention from an otherwise very, very  good model.  

 

As far as firing is concerned, the flap is perfectly designed to partially restrict airflow, but not to fully block it. Secondary air is crucial to the proper combustion process of the coal. The great myth is that we burn coal; we don't. Coal is heated up to drive off the carbon gasses, which combust within the upper reaches of the firebox and tubes.  Coal as such, although burning, is unburnt carbon.  Putting on fresh coal is just the first part of the process of combustion.  A too thick fire can actually cool down the heating process, as not enough Oxygen can get through the firebed.  Too thin a fire will have the same effect, but in the opposite way.  Too much air, in this instance will cool down the process just the same as too little air.  As usual, finding the balance  is the key.  I used to teach trainee firemen about how coal burns. Or rather, doesn't burn. 

 

The locomotive dampers, blower,  grate, firedepth, firebox doors, plus the flap and the shovel all go to fine-tuning the fire to get the maximum output  (if required ) for any given situation. 

 

Then, there's the brick arch, combustion chamber (if included )  water level, quality of water-borne inclusions.....

 

Oh, and working with drivers who haven't got the first clue about driving..... 

Link to post
Share on other sites

1 hour ago, tomparryharry said:

  I used to teach trainee firemen about how coal burns.

 Wow! Respect! Was that on a heritage line or back in the 50s/60s on the 'proper railway'?

 

 

There is a commonly held believe that the fireman is just 'the dumb guy who throws the coal in'. Having read all the Harold Gasson books about footplate life on the GWR I knew there was a lot more to it than that.

 

When I eventually had my chance to work on preserved locomotives , I was astonished just how much is actually going on on a steam loco footplate. You can't afford to 'day dream' or switch-off for a minute. The driver may be carrying all the responsibility, but the fireman has to know almost as much as the driver as events unfold minute by minute. Here is what you inner monologue might look like: 

 

"Is the pressure gaining, steady to falling? What's my water level? Is that reading accurate or is it being affected by the gradient? Has that injector picked up or we just wasting precious water onto the ballast? Is there an adverse gradient soon? I need to build my fire a minute or two before we get there....What aspect is the next signal? I need to shout it to the driver... How's the fire looking? Is it looking thin in places? Do I need to drag some coal forward. How much water is left in the tender? Have we got enough to get to the next water column?............"

 

On and on it goes. You have to have your wits about you all the time. Obviously, the more experience you have it becomes more automatic and easier. That said, the footplate is no place for 'the dumb guy who just throws the coal in'.

 

I hope this is of interested and apologise to anyone who feels it's inappropriate or off topic.

 

Andy.

 

 

  • Like 4
  • Interesting/Thought-provoking 1
Link to post
Share on other sites

The driver just makes it go, and, if he's any good, stops it properly; any idiot can do that!  I have always considered the true skill to be firing; you have to have an eldritch comprehension of what is going on in the firebox and the boiler, as well as anticipating your driver's next move (and we've already established that he's an idiot...).  A good driver will take account of this in his driving technique, conserving steam to the best extent that the load and the timetable will allow, but not all drivers are good, despite what most of them think!  Coal quality makes a massive difference to the firebox's steam raising capability as well. 

 

I was once told that the job of the driver is to stop the train at the correct places and times in the WTT, and the job of the fireman is to ensure that a proper level of water is maintained in the boiler at all times.  This is a different way of thinking about the jobs and most illuminating!  In order to stop the train at the correct places and times, the driver has to of course first start it from the last stop and drive it accordingly.  In order to maintain the correct level of water in the boiler, which will go too low if the driver's activity is not countered by injection water to convert to steam, the fireman has to light and manage the fire, but these are ancilliary activities to their main responsibilities. 

 

In a sense (and sometimes in actual fact!) the driver and fireman are working against each other, the driver continually trying to empty the boiler of steam and the fireman continually trying to provide more.  Successful locomotive operation means that they have to sort of get inside each others' minds, and anticipate what will happen next so that the fireman provides enough steam for whatever the driver wants to do and the driver uses the steam with consideration for his fireman.  This is why locomen do not like changes to routine or working with partners they are not already completely familiar with and can implicitly trust to make the next move as expected. 

 

The driver is senior and in charge of the locomotive; everything behind his rear coupling is the responsibility of the guard, so the fireman has no say in matters when push comes to shove.  The driver who chalks a line down the centre of the cab floor and then expects full cooperation from his fireman is never going to get it, though; in the real world the job has to be done with a bit of give and take, so long as it is understood that a ship can only ever have one captain; it's teamwork.  There is the world of difference between a friendly driver suggesting technique to a rookie fireman, and an authoritarian demanding that he does the job in a way alien to him. 

 

There is no doubt from anecdotal evidence that some steam drivers were very unpleasant people, and these men had usually learned their bad habits from previous very unpleasant drivers back in the days when they were firemen and are now getting their revenge, on the wrong people.  This sort of thing tends to tbe self perpetuating.  A good driver is usually a good fireman who fired to a good driver; best practice is also self perpetuating.

 

Firemen are not dumb guys who shovel the coal in.  Actually, some are, but these do not thrive.  On a steam railway, and from a guard's point of view, they are the grade that gets the most of my respect.  There can be few jobs that require this degree of physical effort and stamina, and mental effort, simultaneously.  It is my view that the obligation of drivers and locomotive designers is to make their lives as easy as possible; this way lies efficient working, a lower coal bill, less pollution, and good timekeeping.

  • Like 2
  • Informative/Useful 1
  • Friendly/supportive 1
Link to post
Share on other sites

Meanwhile, back with Cwmdimbath's new 94xx...

 

It is said that the master carpet weavers of old Persia deliberately included one false stitch in each carpet they made, as perfection is for none but Allah.  So, now that the initial excitement has died of a bit, what do I think that Bachmann have done to avoid blasphemy with this loco?

 

Not very much, in fact.  I have managed to include some of the detail that Bachmann said I couldn't while retaining the tension lock couplings, and have no problem on my layout's minimum no.3 radius fiddle yard turnout.  The firebox glow is not intrusive, but if we must have it I'd prefer it to be orange rather than red.  I think a sliding cab roof ventilator might have been included; my Hornby 5101 and Bachmann 82xxx have them, and getting the crew into the cab requires gyneacological training.  The cab doors were awkward to fit, and I had to use a bent nose pliers to attach them from the inside of the cab through the cab side opening; there seems no way of getting inside the cab without breaking the rear spectacle plate, or of removing the coal load.  The coal is the same sort of metal lump used on the other Baccy panniers and looks not too bad, but I will be putting some of the real thing on top.

 

These are carping criticisms of a fine model, which looks and runs superbly.  I am very happy with my 94xx.  The Precioussssss...

 

If anyone wants a set of etched red backed 9487 number plates with a RSH works plate but no smokebox number, PM me; I won't be needing them and they are a rather nice set which would be a shame to waste.  Perhaps they could find a home on a Graham Farish, Wills/Southeastern, or Lima loco on someone's layout.  I don't want anything for them; SAE and they're yours first come first serve.

  • Like 3
  • Friendly/supportive 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...