ramone:
I don’t think you are distracting from AEC on this thread , the Atlantean was probably a relevant reason why AEC disn’t survive , obviously not the main one but a factor all the same. What was the problem with the Atlanteans in their LT lives , were they unreliable?
Having had a look through some of the information I have to hand I can make a case for the Atlantean and Fleetline story in the London area being relevant to the story of AEC since one particular aspect affected AEC products as well.
Some of the following comes from the memoirs of Colin Curtis (40 years with London Transport SBN 0 86317 156 7) a one time head of the experimental shop at LT and a former AEC apprentice and member of AEC’s own experimental department. For those with a keen mechanical interest this is worth borrowing from the Library.
The conclusion drawn, after the comparative trial between the Leyland Atlantean (XA) with Leyland 680 power and the Daimler Fleetline (XF) with Gardner 6LX power, was after having swapped members of each class from Central London to Country Area work, that the XF was the more suitable vehicle having been more reliable. The most serious issue with the Atlantean was also apparent with the experimental batch of AEC Reliance chassis LT had tried and was to affect the large numbers of AEC Swifts LT was to buy. The problem occurred in Central London and to a lesser extent in the Country Area as well. The Atlantean AND the AEC Swift incorporated a “Power Pack” : Engine fluid Flywheel and Planetary gearbox all in one bolted-together lump. When the vehicle was held up in trafffic, waiting at bus stops for large numbers of passengers to get on and off, or inching forward in traffic queues, the engine/ transmission compartment temperature went through the roof, this particularly so when the bus was idling in-gear. The accompanying thermal expansion acted along the axis of the crankshaft. Severe failures resulted - crankshaft thrust bearings failed as did flywheels with often catastrophic damage. Part of the cause was Leyland induced, the fluid flywheel casing was an aluminium alloy which expanded more than the AEC cast iron version. The Leyland control mechanism for the SCG gearbox also produced very jerky gearchanges - on a par with the severity which had afflicted the first RMs and earned them the nickname of “Jerkmasters”. The poor ventilation in the engine compartment also caused cooling system overheating as well. To a lesser extent similar problems were encountered elsewhere. In an attempt to overcome the thermal expansion problem Leyland, possibly with LT involvement devised various equally ingenious but troublesome centrifugal clutches.
The Fleetline adopted a more traditional layout and separated the transmission from the flywheel with a spider-like coupling. This did away with the thermal expansion issue but coupling life was short, depended on accurate alignment between engine and gearbox and failure could result in bits of it being launched into orbit. The propensity for both Leyland and Gardner engines to puke oil meant that engine mounting rubbers became soggy very quickly thus aggravating the poor couplings working envitonment. Several different designs were tried, but this was the model’s main failing throughout its production. More serious were issues with the SCG gearbox which became evident when large orders for Fleetlines as the DM and DMS class were introduced. London bus drivers were used to Routemasters, the gearbox had been designed to operate ’ in the London way’ - full throttle gearchanges.
In full London spec the DMS was two tons heavier than an RM unladen. The Daimler version of the SCG gearbox “employed a technical operational feature which was most undesirable for London operation” (C. Curtis ) - exactly the opposite of what was required. Curtis took the Daimler Experimental Engineer for a demonstration drive: " I can see poor George sitting there now, holding his head in his hands". The brake bands, clutch plates and internal linkages suffered grieviously from this treatment, which was eventually improved by various modifications. However Leylands decision to transfer production of the Fleetline from Daimler’s Radford Works to Farrington destroyed the working relationship between customer and manufacturer. In a ‘we know best attitude’ typical of Leyland, a rationalisation of production methods and a modification to parts specification resulted in a return to the previous issues putting brand new buses off the road very shortly after entering service.
Apart from the above LT’s DMS class were hindered by LT’s attempts to speed boarding times with automatic fare collection equipment. This suffered indigestion when subjected to the forces involved in a moving vehicle, meaning that the actual boarding time increased because the equipment was in the way.
As said the AEC Swift in its ‘Merlin’ guise especially, suffered from the same similar Power pack induced issues as well as its own problems with the persistent coolant fan drive failures. Leyland’s arrogant attitude returned to blight the Swift. The same Leyland modifications were re-introduced to the SCG gearbox and even worse the Leyland ‘rationalised flywheel’ complete with aluminium casing was reinstated with the predictable results. The adoption of an earth return electrical system caused numerous shorts and even some fires. Fires were also started by a change to the source of inlet air for the compressor from atmosphere, to coming instead from the inlet manifold. Oil contamination of this air resulted in hot carbon ejected by the compressor either bursting the rubber compressor delivery pipe or blocking it. In the case of the latter red hot carbon was ejected at considerable velocity by the system safety valve into an already very hot engine compartment liberally coated with dust, debris and oil .
While surely 7 spares available to meet a 120 loss for service = a ‘shortfall’ of 113 ?.As opposed to the RM’s 53.
That type of stupid can only be explained by intent with foreseeable results.