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Dapol Class 21/29


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On 18/12/2019 at 18:08, G&A Track said:

Dapol just updated their facebook page Class 21's now on there way to all good Dapol Stockist.

 

There we go...

 

From announcement on November 20th 2010 until December 17th 2019..

3315 days

or

9 years, 28 days.

 

looking at BR Database that’s just about equal to the service life of D6117, from 16/06/1959 to 16/08/1968.

 

D6117 was the 36th member of the fleet to be withdrawn.

 

Personally, my child was a few months old when these were announced, but knew what a class 21 was and how unreliable they were as a 9yr old at Warley last month.

 

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15 hours ago, Neil Phillips said:

Strange, isn't it, that although other Type 2s sported either an off-white stripe or lighter-green band on their dark green livery, the NBL Class 21 had neither and the Class 29 had both! ...

The KX area collection of early type 2 diesels for the suburban service was characterised by our little gang as two stripe, low stripe, high stripe, no stripe. Clearly the more and higher stripes indicated superiority, because these were TOPS 30/23/26/21 respectively. When the class 24 showed up it too was low stripe, and such a duffer that it wasn't even tried on the suburban turns... And now we have them all in current standard RTR, who'd a thunk it!

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15769416300328288056616037868044.jpg.c03ae64d2ef79d6e33f1dddc263c7bb9.jpgAfter having chance to look at the model today I would say it's superb apart from a couple of minor niggles ( I won't comment on body being right etc as I don't know if it's right or not)

1st there s no instructions for mounting the headcodes discs or buffer detail. Not a great problem if u have access to pics I suppose but could catch 1 or 2 out e.g. disc folding to the side not up like a cl20.

Also disappointed that there 7 open and only  3 closed discs. Ok not a problem if u have a spares box, or feel comfortable cutting a full 1 in half I suppose. Also that the closed discs are painted white not yellow or green as per body colour surely it wouldn't of cost a huge Amount to supply 8 closed discs (either all green or 2 green,6 yellow depending) that way u won't have to try matching the factory colour. 

The supplyed hook for the 3 link seem a tad to big and fouls on the bottom of the cab front which would make things a bit difficult in real life. (Again having a spares box comes in handy)

While there is a fine mesh scavenger fan grill there's no (on mine anyway) fan under it and u can see the wires for the lights through it. Now of course I don't know if this is just missing on mine or an ommision in general as I take it the speaker would sit on chassis under the grill. So perhaps some one could comment if theirs has 1.

Thank you Dapol for finally producing this class and can't wait for the 29s to follow.

1576941593153158761532581660146.jpg

Edited by Gareth 73
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Got one from Monk Bar models today. Very pleased with it.

 

My two niggles are the windscreen wipers, which are far from subtle, and the glazing, especially on the body side, which looks like something on a GBL model.

 

Both these stood out even three feet away when the shop was testing it. 

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Well, first ever Dapol loco purchase and I am favourably impressed. Side glazing the only significant negative, massive lensing. But looks right overall, neatly finished, runs smoothly and quietly; that's the ticket. I had thought from the photos seen online that the wheels were solid, however they are spoked, although this detail is almost concealed by the bogie frames.

 

I guess that body removal for decoder fitting is the usual ease body side away from mechanism to unclip, that can wait until tomorrow.

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Temptation looms large. A question though, what are the prospects for conversion to EM or P4? Is there room in the bogie frames for a wider gauge or will the files need to be brought out?  Also, how is electrical pickup organized? Are the wheels mounted in separate muffs or on a single through axle?

 

TIA

 

Cheers,

 

David

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5 hours ago, davknigh said:

...what are the prospects for conversion to EM or P4? Is there room in the bogie frames for a wider gauge or will the files need to be brought out?  Also, how is electrical pickup organized? Are the wheels mounted in separate muffs or on a single through axle?

There's 23mm between the cosmetic bogie frames at the wheel positions, ample to take EM or P4 wheelsets.

 

Split axle electrical pick up. There's continuity from tyre to the brass collar in which the axle runs.

 

I have not ventured to take the cosmetic bogie frames off the gear towers, construction is a tad cryptic, so cannot tell exactly how the wheelsets are constructed.

 

The body doesn't appear to be held on by any clips and detents arrangements, but is simply so snug a fit on the cast chassis block that it 'stays put'. Easing the sides outward released the body very easily. Very neat and tidy interior construction. Body is tethered to chassis by lighting wires, all on plug and sockets so that separation is simple.

 

Installed a Zimo MX 638 and it operates very smoothly indeed, mechanism nearly silent even at maximum speed now; having accumulated two hours operation the loudest sound is the wheels on the rails.

 

Like it very much indeed.

 

4 hours ago, Nimbus said:

I would be interested to hear how easily the cabside numbers come off, as no GN candidate Cl 21s have been scheduled...

Indeed, another GN section type here with the same thought. I think we ought to throw this question open to those experienced in all things Dapol. And another thing, no assembly/parts diagram. Is that normal with Dapol?

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For the Paxman engine sound, I would have thought possibly something like an HST sound without the turbo scream might be close. However, as none of the 29s survived, there is no way of being sure of the sounds. 

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Hi Richard. Type YJ (Ventura) was used in a number of Applications. As always, it’s not the loco that’s important, it’s the engine that gives the sound personality. I would think a HST is closer -but it’s a guess! Wiki: 

 

The engine as originally fitted to the HSTs was designated 12RP200L and was a V12 four-stroketurbo-charged & intercooled diesel unit of 79 litres which developed 2,250 bhp at 1,500 rpm. The design of the Valenta was based on the Ventura which was fitted to the Class 29 diesel locomotives, amongst others. The engine is famous for the "Valenta Scream" on starting from rest, a distinctive high-pitched whine caused by the engine's turbocharger.[2][3]In 1977, the Valenta received the Queen's Awards for Enterprise.[4]

 

Anybody know a Ventura in use as a Genset? 

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10 hours ago, Richard Croft said:

Hi, thanks I used that when I made the 22, and the 21 which is a diesel electric version. The 29 was re engined though.

 

Richard

I’m given to understand that a diesel hydraulic revved up more on starting than a diesel electric. Are experts able to confirm that?

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Further to recent comments regarding the full yellow ends (fye) on forthcoming Dapol Class 29 models.

The fye on D6129 being an Inverurie BFY repaint is correct in having the "stepped" boundary near to the bottom corner of the driver/secondman windows.

However the stepped boundary is NOT correct on (D)6112 (GFY) and (D)6107 (BFY). Both of these were Glasgow Works repaints. D6107 received BFY on conversion to a Class 29 in June 1967, with (D)6112 getting its fye (on the pre-existing green) during its first Classified repair as a Class 29 in June 1971.

To help illustrate the point, photos of D6107 and 6112 appear on pages 224 and 63 respectively of the recent Pen & Sword book "The North British Type 2 Bo-Bo Diesel-Electric Classes 21 & 29". Similarly D6129 on page 108.

Hopefully the errors on (D)6107 and (D)6112 will be corrected by Dapol before their release in 2020.

I've already pre-ordered D6114 and D6129, but I'm waiting to see how the shipped 6107 and 6112 models have been painted before ordering.

Hope this helps.

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19 hours ago, davknigh said:

Temptation looms large. A question though, what are the prospects for conversion to EM or P4? Is there room in the bogie frames for a wider gauge or will the files need to be brought out?  Also, how is electrical pickup organized? Are the wheels mounted in separate muffs or on a single through axle?

 

TIA

 

Cheers,

 

David

I've started to convert D6116 to EM using its original wheels, which I am turning down to a more acceptable profile. There is plenty of room  between the bogie frames for the original wheelsets opened out to EM. The wheels are mounted on stub axles that push into the center plastic tube/gearwheel, and haven't given me much problem, although I'm not 100% convinced of the quality of the wheels themselves. The pickup is by a metal "busbar" that fits just inside the frame, and interacts with the brass bearings, a possible cause for problems in the future??. The grease on my example was applied very sparingly, so no issues there. The whole wheelbearing/pickup does need close attention when the wheelsets are opened up, as the axle has a lot of play on it, so I'm still experimenting on the number of washers on the axle to give the best performance. Note the bearings go a certain way, so pay attention to them when taking apart and putting the axles back together. The bogie sideframes come off the bogie easily by carefully leavering them out at the ends. I found the inside end the best, but be careful when putting them back together, as the gear towers on mine started to come apart when the bogie frames were taken off.

 

The body is held in place by 4 clips above the inner wheelsets. My method of taking the body off was to insertion of a small flat screwdriver adjacent to where the clip is to open the body away from the chassis and insert a thin cardboard strip to stop the clip re-engaging and repeat for all 4 clips. The body came off easily on mine, but watch out as there are a lot of wires connection the body to the chassis that need to be unclipped from the circuit board.

 

I hope that answers some questions that may be out there. And yes to someone elses post I spotted, the headcode discs are rubbish. Some spares from my collection of SLW 24's are probably the answer. to that problem.

 

Paul J.

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5 hours ago, miles73128 said:

Hi Richard. Type YJ (Ventura) was used in a number of Applications. As always, it’s not the loco that’s important, it’s the engine that gives the sound personality. I would think a HST is closer -but it’s a guess! Wiki: 

 

The engine as originally fitted to the HSTs was designated 12RP200L and was a V12 four-stroketurbo-charged & intercooled diesel unit of 79 litres which developed 2,250 bhp at 1,500 rpm. The design of the Valenta was based on the Ventura which was fitted to the Class 29 diesel locomotives, amongst others. The engine is famous for the "Valenta Scream" on starting from rest, a distinctive high-pitched whine caused by the engine's turbocharger.[2][3]In 1977, the Valenta received the Queen's Awards for Enterprise.[4]

 

Anybody know a Ventura in use as a Genset? 


The engine is only one part, the turbo makes a huge (and often more significant) difference to how a loco sounds as does the exhaust fitted. 
 

Roy

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3 hours ago, No Decorum said:

I’m given to understand that a diesel hydraulic revved up more on starting than a diesel electric. Are experts able to confirm that?

 

As a general principle you can apply full power to a hydraulic transmission at standstill - as a torque converter has no direct mechanical connection energy not transmitted from the impellor to the turbine and hence to locomotion via the cardan shafts and final drives is converted to heat and dissipated via the cooling circuit.  Misuse of any transmission will cause problems however and bent cardan shafts in Hymeks (the most powerful single engine/hydraulic transmission set installed in UK) were not unknown.....

 

You cannot apply full power to an electrical machine at stand still for long however as without motion the armature and field coils are permanently in circuit until the motor starts to rotate and will function as resistors and generate heat for which there is no immediate direct dissipation - melt down would follow. Current limiters in control circuitry are required to restrict this risk.

 

Furthermore individual axles cannot slip on a bogie with hydraulic transmission as they are all directly connected by cardan shafts - not the case on a diesel electric with individual traction motors - so a hydraulic can theoretically better utilise its tractive power although sophisticated control circuitry on later diesel electrics helped alleviate this issue.

 

Heres D1015 demonstrating hydraulic starting power ... the dip in engine sound as the converters fill still makes my spine tingle

 

https://www.youtube.com/watch?v=5FDC0JFNqAI

 

Can recommed a visit to Kidderminster Diesel Depot when one of the Wizzos is up on the jacks to get a good view of hydraulic power trains.....

H

 

 

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45 minutes ago, miles73128 said:

Yes. It will. And the exhaust. 

 

And the transmission too .... and as good as many DCC sound files are I have yet to be convinced by either hydraulic transmission changes or field diverts on electric transmissions....

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1 hour ago, Roy Langridge said:


The engine is only one part, the turbo makes a huge (and often more significant) difference to how a loco sounds as does the exhaust fitted. 
 

Roy


indeed

 

this is what a class 40 sounds like if you don’t factor in the turbo and exhaust.

 

 

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1 hour ago, Roy Langridge said:


The engine is only one part, the turbo makes a huge (and often more significant) difference to how a loco sounds as does the exhaust fitted. 
 

Roy

+1 for this. Dedicated Cl.56 fans with a keen ear will be able to tell you if a particular loco was fitted with Napier or Brown Boveri turbos. One would produce the distinctive scream many associated with the type but the other allowed the deep V16 rumble to permeate.

Not seeing the point of sound fitted models anyway, my guess is that the Cl.56 sound files available are from whatever prototype machine was recorded, regardless of turbo's fitted.

You've heard of rivet counting, sound wave pedantry anyone?!

 

C6T. 

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2 hours ago, Classsix T said:

...You've heard of rivet counting, sound wave pedantry anyone?...

There's an entire dictionary of aspects of sound reproduction for keyboard warriors to wield as weapons while trading insults, available fully developed and FOC from the sphere of high fidelity sound reproduction.  We'll know it has really taken off when the DCC sound advocates start insisting on cable-sexing between the decoder and transducers, and the like...

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