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PostPosted: Thu Jan 30, 2014 1:56 am 
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Posts: 39
Location: Mount Maunganui, New Zealand
A liitle more on the Christchurch AEC Regal IV and Reliance fleets.

The Regal IVs were 95 in number, the first 39 with Crossley bodies and the remaining 56 with Park royal bodies. They had the standard wheelbase, 17'6", and 33 ft bodies. (In fact the long version with 19'6" wheelbase did not become available until about the time the Christchurch order had been delivered.) All had the 9.6 litre engine. Even in mostly flat Christchurch with its relatively slow-moving traffic, they were considered to be rather slow.

The "short" Reliances were 27 in total, in two batches, all with 30 ft Park Royal bodies. The first batch of 17 were of the MU2RAE variety, with 16'4" wheelbase. The second batch of 10 were HMU2RA, 16'0" wheelbase option.

The "long" Reliances were 20 in number, 33ft Park Royal bodies on 17'6" wheelbase HMU2RA chassis.

The 24 "new" Reliances had NZMB 33 ft bodies on 17'6" wheelbase 2HMU2RA chassis.

The 33 ft, 17'6" wheelbase version, which was the second length available after the original 30 ft/16'4" wheelbase model, seems to be overlooked in much of the literature.

For example, it is stated in Wikipedia:

"Following successive changes to Construction & Use regulations, the maximum length of the Reliance was increased twice from the original 30': firstly, to permit an overall length of 36' from 1962;[5] and later, to permit a length of 12 metres."

Fail!

But it illustrates the big problem with Wikipedia. Only reliable secondary sources may be used, which means that errors and omissions in acceptable references tend to be perpetuated.

Wellington had 67 30 ft, 16'4" wheelbase MU2RAE with MCW Hermes bodies as its "Mk I" Reliance, and 44 30 ft, 16'4" wheelbase 2MU2RAE with NZMB bodies as its "Mk II" Reliance fleet.

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PostPosted: Thu Jan 30, 2014 9:01 pm 
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Joined: Sat Mar 31, 2012 7:34 am
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Location: Mount Maunganui, New Zealand
More on trolleybus motor power outputs, the UK electrical equipment makers did seem to offer about the right range in the early 1950s.

For example, an English Electric brochure, undated but triangulated to circa 1950, shows a range of 120 to 150 hp for its newest motor, which would have been the 410 series, comparable to the BTH/MV 210.

Attachment:
EE Trolleybus Equipment p.01.jpg
EE Trolleybus Equipment p.01.jpg [ 1.42 MiB | Viewed 1976 times ]


Attachment:
EE Trolleybus Equipment p.05.jpg
EE Trolleybus Equipment p.05.jpg [ 1.15 MiB | Viewed 1976 times ]


BCVI 4th, 1953, notes up to 140 hp for BTH, 140 hp for Crompton Parkinson, 120 to 150 hp for EE, 70 to 150 hp for GEC and 95 to 135 hp for MV.

By BCVI 7th, 1959, BTH had a 160 hp motor and the GEC range had been extended up to 175 hp.

US practice in the “classic” post-WWII era was defined by the two equipment suppliers, GE and Westinghouse. GE offered a 140 hp motor with its MRC control system, and Westinghouse a 125 hp motor with its (reputedly very good) Super Electrocam control system. These were higher-speed motors than those of UK origin and consequently were coupled to drive axles of greater reduction.

In the same period, US transit-type motorbuses were often fitted with gasoline engines of 200 hp or more. Some diesel engines might have had lower output, for example the Detroit 6-71 was 165 hp originally, but the 200 hp number was reached and exceeded fairly early on.

Comparison of trolleybus motor power and motorbus engine power is not an exact science. In the trolleybus case, the usually quoted power output is the 1 hour, full-field rating, which for British vehicles corresponded with a speed in the vicinity of 12 to 13 mile/h. The typical three weak field notches provided another three points on the curve where maximum power was available, perhaps up to the high 20s mile/h or even low 30s mile/h, with some drop back down the sawtooth to the switching points. Once at full weak field, the motor was running on its curve, very approximately inverse square law, so available power was diminishing quite rapidly. Initial acceleration through the resistance notches to full field was done at nominal constant current, constant torque, although the relatively coarse steps meant that the curve in practice was a sawtooth.

In the motorbus case, the power output usually quoted was that for the engine at its rated speed, available only at the maximum speed for each gear. With a typical 4-speed epicyclic gearbox with 60% ratio steps, and let’s say overall gearing for a maximum speed of 45 mile/h, the maxima in 1st, 2nd and 3rd would be around 10, 17 and 28 mile/h respectively. Immediately after each upshift from the maximum in the previous gear, the engine was operating at 60% of rated speed and say around two thirds rated power.

In terms of initial acceleration and hill-climbing, a trolleybus with around 130 hp would easily outperform motorbus of around 150 hp, and that something like 200 hp or more might be needed to match performance. On the other hand the 150 hp motorbus would have the advantage at the higher speed end of the range. Let’s day that the 130 hp trolleybus has a full current, full weak field speed of 30 mile/h, at which close to 130 hp is still available. By the time it reaches 45 mile/h, on the motor curve, power will have fallen to around 60 hp, whereas at that speed the motorbus has its full 150 hp available.

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PostPosted: Sun Feb 02, 2014 2:08 am 
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Joined: Sat Mar 31, 2012 7:34 am
Posts: 39
Location: Mount Maunganui, New Zealand
More on braking systems:

The attached Clayton Dewandre (C-D) advertisement from BCVI 5th, 1955 is interesting, and shows a progressive stance on the use of air brakes, including the air-actuated hydraulic system which one may infer was aimed at the 7-ton vehicle class, and before the end of the decade had been adopted by both Commer and Dodge amongst the mass-producers. C-D had evidently gotten past the NIH syndrome, and that the advertised air brake systems were of American design was presented as a beneficial feature.

Attachment:
BCVI 5th 1955 rp.33.jpg
BCVI 5th 1955 rp.33.jpg [ 992.22 KiB | Viewed 1973 times ]


Vacuum was not entirely overlooked, though, and the Hydrovac was included. Of course, suspended vacuum was the better way to go if vacuum was to be used at all, and in retrospect one may wonder why C-D did not develop a suspended vacuum version of its triple servo system. But doing that may have been something of a gamble, insofar as the operators that chose vacuum for their urban buses were likely those who looked ahead via the rearview mirror, and would resist anything that did not date back to the 1930s or even earlier.

The Lockheed advertisement from the same book featured the Powervalve hydraulic system, but also included the Hydrovac.

Attachment:
BCVI 5th 1955 rp.28.jpg
BCVI 5th 1955 rp.28.jpg [ 996.55 KiB | Viewed 1973 times ]


Whilst the Lockheed hydraulic system may have been looked upon with some disfavour as being rather complex, it might be noted that constant flow hydraulic systems are the norm for much mobile off-highway equipment, including the largest minehaul trucks that carry 300+ tonnes. As well as the braking systems, the central hydraulic systems often operate fully-powered steering systems as well. And these vehicles operate under much more difficult conditions than do on-highway vehicles.

Here is an interesting item on the Airpak unit from Bus & Coach, 1960 September. The theme was air-is-better-than-vacuum.

Attachment:
CD Airpak B&C 196009.jpg
CD Airpak B&C 196009.jpg [ 1022.64 KiB | Viewed 1973 times ]


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PostPosted: Sun Feb 02, 2014 9:24 pm 
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Joined: Sat Mar 31, 2012 7:34 am
Posts: 39
Location: Mount Maunganui, New Zealand
Stephen Allcroft wrote:
The national union-management agreement also explains why instead of the Panther being proposed to it (and most of the other larger Leyland customers) Manchester Corporation asked for a 33ft version. A Panther driveline layout could not accommodate the 600 or 680 to a 33ft length without breaking UK C&U rules on rear overhang. Manchester outright refused Panthers and said to Leyland that they had been briefed on a rival product (the Daimler Roadliner ) and it was available at 33ft. This is the wherefore of the most woeful failure of all post war Leyland Motors or LMC single deckers, the Panther Cub.


The “failure” of the Panther Cub was a fairly predictable, and I suspect was expected by the Leyland designers. It was another case of design effort being wrongly directed (wasted) and for the wrong reasons. The Lowlander and Renown are a couple of other examples. Whilst I should not wish to go as far as saying that the customer is not always right, a wise business chooses carefully those customer-requested projects that it pursues, particularly where these are driven by somewhat arbitrary external conditions or historical preferences that are out of their time.

I do not think that the Panther Cub was inherently flawed, any more than any other Leyland Group buses powered by the small engine. Rather the problem was that its nature, specifically the low frame ahead of the rear axle, encouraged the fitting of body types that were suitable for use in frequent stop, heavily loaded urban service, for which an altogether higher-powered vehicle was really required. To that was added the apparent inability of UK operators, unlike those in Australia, to get the best out of the Panther/Swift in any form. Hitherto the small engine had been available in Leyland/Albion and other buses of varying degrees of sophistication, including the Albion Victor and Clydesdale, Leyland Comet, Bedford SB8 & SB13, Dodge S306 & S307, Albion Viking, Bedford VAL14 & VAM14, Tiger Cub and Bristol LH. As far as I know all worked well enough when appropriately deployed, although the VAL14 was a borderline case. I understand that some ex-UK Panther Cubs went to Australian private operators, where they were satisfactory as deployed, not in urban service. And apparently some of these were fitted with two-speed axles, which although in and of itself a very good idea where the small engine was concerned, surprised me as it is not something that I should expect that many UK operators would have specified. By the way, I think that the Panther Cub frame differed from that of the 33 ft Swift in having an inset at the left rear in order to accommodate the crossflow version of the O.400 engine.

Attachment:
Panther Cub B&C 196409 p.320.jpg
Panther Cub B&C 196409 p.320.jpg [ 281.35 KiB | Viewed 1968 times ]


The bigger issue here, where Leyland missed the boat somewhat, was in the original Panther design, which was something of a “quick and dirty” rearrangement of the Leopard/Worldmaster concept to have a rear engine, and in the bus case, borrowing the Atlantean forward frame layout. On the other hand many overseas operators were looking to step up to a somewhat more sophisticated rear-engined vehicle, which requirement was well met by the very successful Mercedes Benz O.305, at least in its 2nd iteration form with the OM407h engine. Here Auckland led the way with its large fleet, installed from 1973, and set the example for Sydney and elsewhere. The O.305’s superior performance and much reduced maintenance requirements represented a big step change. Leyland meanwhile had put its efforts into the National, which was of virtually zero utility in the export market.

Stephen Allcroft wrote:
He does mention the 1975/6 South African double deckers but not the later CMB/KMB and other Hong Kong examples. These, the Victory 2 series II, had Worldmaster CRT, rather than Guy Big J-style frames to reduce overall height, and the vast majority had Voith D851 transmission; all were 6LXB powered and the vast majority had locally assembled Walter Alexander CB-type CKD bodies, the rest similar units supplied by Duple-Metsec. It was a reliable bus but far from a stable one, the Wikipedia article ‘Leyland Victory’ contains a list of all the overturning incidents involving the type.


The Victory double-deck episode was another example of misdirected engineering effort, but in a situation of Leyland’s own making. In South Africa at least, the extremely poor performance of the Atlantean and Fleetline vehicles had created the belief in some quarters that their problems were fundamental to their rear-engined layout, and that the only solution was to place the engine at the front. This was very blinkered thinking. One only had to look to North America to see that the transverse vertical rear-engined layout, used since the 1930s, was eminently successful for urban buses operating over an extreme range of ambient conditions and not only with the relatively inefficient and therefore high heat rejection Detroit Diesel two-stroke diesel engines, but also with torque converter transmissions. Leyland really had no good engineering excuse for not getting it right with the Atlantean very early on; thus one assumes that by the mid-1950s, the lack of adequate investment funds was already a problem, and the malaise leading to eventual demise had already set in. Daimler one should have expected to have had difficulties basis the Freeline precedent. In both cases the makers probably set themselves a more difficult task by choosing to use the air-operated Wilson gearbox. Whilst a much more modern epicyclic device sans bands would have been preferable, the oil-operated version of the Wilson might have been better.

So, poor engineering of the British rear-engined chassis led to customer rejection of the concept as a whole, and not just the specific implementations. That said, the total market for the Victory double-deck variant was quite small, and did not justify much engineering effort. What was done was probably more than was really supportable.

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PostPosted: Thu Feb 06, 2014 3:13 pm 
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Posts: 169
Further for 9711T
Interesting selection of Locomotives in the Vacuum Brakes advert, in particular a CIÉ class A Metrovick-Crossley, the advertisement is dated 1962. In 1960 an order was placed by CIÉ with General Motors EMD for short-notice delivery for 15 single cab 950bhp Bo-Bo 75mph road-switchers (12 delivered the same year) because of the problems with the Crossley 1,200bhp HST VEE8 engines in the 60 class A Co-Cos delivered only three years earlier. Eventually CIE and the folks at GM got on so well that they were the first railway out of the US allowed to re-fit GM EMD diesels in existing third-party locos, and the A-class when re-engined (with power units between 1,200 and 1,650bhp) finally became reliable locomotives, in the process vindicating Metrovick, whose electrical equipment stood up to the uprating with no trouble. The C-Class Metrovick Bo-Bos were uprated from 550bhp Crossley to 1,100bhp GM, the electrical equipment unaltered, coping with Dublin’s suburban services until the late 1980s. Irish locomotives (until the late-1994 201 class for the de Dietrich ‘Enterprise’ push-pull sets) did not provide power for passenger-carriage light and heat, instead brake vans (4-wheeled into the 1960s) carried generators and steam-heat boilers. As the GM era wound on, the electrically heated BR Mk II brakes used the Detroit Diesel 6L-71 to drive a generator to provide passengers with heat and light. Thus circa-1975, the CIÉ relationship with Leyland reaching breaking point, the new Van Hool designed buses were to have a 6V-71engine and an Allison V730 transmission. At the time Detroit and Aliison were, like EMD, wholly-owned General Motors Corporation subsidiaries although US anti-trust laws mandated their availability to other manufacturers.
Van Hool pulled out of Ireland in 1978, having bodied the CIÉ AN68s, an Atlantean and 65 Ailsas for South Yorkshire, two similar for A1 Service in Ayrshire, and some 300-series coaches for British Isles operators, the majority on Ford and Bedford but a few Leopards, Reliances and Volvo B58s. For a while afterward they supplied the British Isles from Spain, The early 800-series bodies were called Aragon in the British isles as a result.
CIÉ, who must have been at the time nearly as railway-dominated as London Transport, decided in 1976 that in order to cure the problems of poor power and endemic head-gasket related overheating on the long C class PSU3/4 Leopards, these would receive 680 engines from the M-class PSU5.4R Leopards (the first built) which would in turn either get DAF DKDL or GM 6L-71s. The DAF Transplant (and the similar one on some PDR1/1A and AN68 Atlanteans) retained the Pneumocyclic gearbox, but the Detroit engines would instead have Allison Transmission. There were also at the pilot stage two Cummins 220 Leopards. The re-engining programme ended in 1981 and produced an M class fleet with four different engines and two transmissions, split Cummins (MC-class)2; DAF (MD) 73; Leyland(M) 54 and Detroit(MG) 84. The MG conversion was particularly time-consuming involving the insertion of a cranked offside frame member; it took two months to re-power each coach from M to MG. The horizontal use of the 6L-71 was uncommon although Detroit had offered it since the 1950s as a repower product for Flxible, Faegol, White and other UFE Transit Coaches. I do not have details, but isuspect that like the Volvo THD100 it was a dry-sump layout.
After one Van Hool prototype had been built by 1977, a dual-door single deck citybus, the Van Hool McArdle company had been declared insolvent and dissolved so CIÉ took another approach, they got a design consultancy (FFG of Hamburg) to design the four standard types required and then let a tender (with substantial Republic of Ireland government assistance) to an international consortium prepared to manage the construction of these types at a former Piano factory in Ballyshannon in the west of Ireland. It was won by Bombardier of Canada in association with General Automotive Corporation of the USA. Bombardier at the time was probably best known for the Ski-Doo. Its French corporate title at the time translates I think as The Bombardier Snowmobile Production Company Ltd (Société Des Produits Auto-Neige Bombardier). GAC later became famous for the Humvee. The initial two classes from 1980 were the 11m KE tours and express coach and the 9.5m KD dual-door double deck, these had the 6V-71 and Allison driveline. However on the public champagne launch of the KE coach, the prototype suffered a mechanical failure. A Dublin paper called it ‘The Streetcar Named Expire.’ The KD was less trouble-prone mechanically but it did tend to topple-over nearly as often as the Leyland (Guy) Victory 2 series II did in Hong Kong. No repeat orders of KEs occurred, the next CIÉ coaches being 12m long 3.6m high Van Hool Integrals (with MAN engines and ZF synchromesh transmission).
The -71 series worked, and worked well in most applications (the only major disaster I know of was Greyhound Lines’ specification of two geared 4L-71s in the GM Truck and Coach Scenicruiser, they received 8V-71s on first overhaul and became legendary) but the MG Leopards, the KDs and KEs did not provide acceptable fuel economy, thus the 10.4m KC class urban single deckers got an inclined (longitudinal?) Cummins LT10 driving a ZF gearbox, and after a trial in the prototypes between a DAF DHU and a Cummins 6BT with Allison AT545 transmission it was the latter used in the most successful of these Irish-made buses, the 9.5m KR class 43 seat rural bus. One of these even spent 18 months on loan to United Automobile Services of Darlington, County Durham where its engine was built. Then a period of austerity left Bus Éireann (the out-of-Dublin bus part of the 3-way split of CIÉ) unable to place further orders and GAC (Bombardier had pulled out earlier) closed the factory in 1985. The demonstrator loaned to UAS rejoined Bus Éireann in 1987.
In 1982 Gavin Booth wrote (In the British Bus: Today and Tomorrow, Ian Allan ISBN: 0 7110 1296 2) that “Ireland is one market that, it would seem, is completely lost to Britain’s bus builders.”
Mr Booth’s carefully qualified gaze into the crystal ball failed him there. Dublin Bus took to the Olympian with Belfast built Alexander bodies (to the tune of 170 Leylands and 465 Scottish-built Volvos) and Bus Éireann dual sourced Cummins LT10H Tigers and DAF MB230s. Currently Scania / Irizar coaches are Bus Éireann standard and Volvo/ Wrightbus double decks are being delivered to Dublin Bus.
When Bus Éireann needed a large number of secondhand school buses they actually became the largest ever user of buses with NZMB coachwork in the Northern Hemisphere, taking all the former Singapore Bus Service Volvo B57s.
The English Electric exports do show how standardised that conglomerate was with Locos. I almost mistook the second picture for a BR Class 40. A group of Diesel preservationists at the East Lancashire Railway obtained the last surviving 9-cylinder Turbocharged Napier Deltic and its EE generator from the Class 23 ’Baby Deltics’ and are cutting and shutting a class 37 underframe and body to fit it, with class 20 Bo-Bo bogies and motors they hope to have a near exact replica restored and running by the end of the decade at rather less cost than the new-built Peppercorn A1 Pacific ‘Tornado’.
The Guy Conquest brochure is it seems prepared for the Benelux market as the impression of the bus on the cover features a Netherlands-style registration (the hyphens are a giveaway) other than that and a less prominent grille, it’s obviously based on the Edmonton and Calgary Roadliner buses bodied by Willowbrook in 1964-66, so was it I wonder the brochure for a Brussels show in 1965, 1967 or 1969?
The MF2B was used by two UK operators as a dual-entrance dual-stair double decker and the chassis illustration (courtesy 9711T) shows how low it was... Hull wanted to use its examples driver-only so equipped them with powered trolley retrievers, front entrance and centre exit with Roe ‘safety staircases’ matching the door positions; the permission was never forthcoming but 1954 when these ‘Coronation’ Trolleybuses were delivered was twelve years before one-person operation of double-deck motorbuses was legalised. Bournemouth worked on a rear-entrance and front exit system with rear and front stairs on double deckers and an open rear platform even on its Royal Tiger and Tiger Cub single deckers. Bournemouth’s MF2Bs benefitted from C&U length relaxations and were 30ft rather than the 27ft of the KHCT trolleys. Two batches were supplied to Bournemouth, the second in 1961, making them the penultimate batch of new trolleybuses built for the UK. Reading’s Burlingham bodied forward entrance F4As followed the year after. The last home market BUTs went to Glasgow in 1958/9, a mix of RETB1s and 9614Ts. The double deckers were among the last bodied by Crossley, although some were finished at Park Royal. The RETB1s, of which two are thought to survive, were bodied by Burlingham, and at 34ft 9in long with 54 seats were the longest single deck vehicles on rubber tyres in the UK. HV Burlingham Ltd had only done one batch of trolleybuses before this, and were only to do one after, these were the only single deck trolleybuses it built; coachwork for Glasgow’s only other single deck trolleybuses (30ft ETB3’s) were one with a Weymann body, the other nine East Lancashire, and they were originally rear-entrance and central exit with a seated conductor but refitted to central entry/exit.
R. Edgeley Cox, the GM of Walsall Corporation, purchased one of the Bournemouth MF2Bs after the south-coast system’s abandonment in 1968 and was in the middle of having it converted to a bi-mode bus, with a transverse diesel engine driving a generator under the seating which would have replaced the rear staircase when West Midlands PTE happened from 1 December 1969 and they decided to close the Walsall trolleybus system during 1970. In Commercial Motor around that time (That publication’s searchable archive is a joy!) he suggested using a Perkins V8 for the project, a previous non-road-legal technology demonstrator he’d had built (in support of a Patent he was applying for) based on a Sunbeam F4 carried a longitudinal 6LW Gardner on a long cantilevered extension to the rear overhang. Recent Classic Bus correspondence attests it was driven as a diesel-electric on an un-opened section of the M6 Motorway.
The Bombardier KD was the largest class of two-stroke double deckers ever built, the Yellow Coach and Truck ‘Queen Marys’ in New York and Chicago built 1934-7 being mainly gasoline-powered (one had a Hercules 4-stroke diesel) and the only Foden PVD having the 4.1 litre 140bhp Foden FD6, KMA750, was new as a Foden demonstrator circa 1949, it passed to an independent in South Yorkshire who were taken over by Yorkshire Traction who ran the Willowbrook bodied bus for a standard service life. The Foden FD, like the Detroit-71 series, was a uniflow-type engine with inlet ports and exhaust valves.
The 1931 Gilford Front Wheel Drive double decker was designed with a Junkers opposed-piston flat four two-stroke, but Gilford never sorted the manufacturing-rights issue, importing the engines would have made the type unprofitable but no orders were obtained in any case thus the prototype was shown at the Olympia Commercial Motor Show that year with a mock-up engine. It is only known to have ran under electrical power, being converted to a Trolleybus working for Wolverhampton as a demonstrator and taken into stock by Southend, whose diverse fleet included the only rear-motored Gloster and lowbridge bodied offside-motored AEC 761T Q trolleybuses. As it also ran conventional AECs and Guys with a mix of normal and side gangway bodies it had a unique distinction in its mix of motor positions, drivelines and body layouts. The Gilford and Gloster were low enough to pass under Sarfend’s railway bridges without a side-gangway upper-deck. I wonder why they did not snap-up the twin-motor Leyland–Massey Low Loading Trolleybus? Maybe Leyland or Massey Brothers wanted too much money for it.
Best wishes
Stephen Allcroft
Cardross
Scotland


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