1950s Battery Multiple Unit

[Swanley 59]

I was reading about recent developments in battery technology for rail when I came across this fascinating article about a 1950s experiment with a Battery MU in Scotland: https://www.railscot.co.uk/articles...BMU:_Notes_on_the_Battery_Railcar_Experiment/

Running a BMU service on a 43-mile branch line was nothing if not ambitious. I was struck by the weight of the batteries required - 17 tons!

I was wondering if any of the many expert and highly knowledgeable contributors to this forum knew why this experiment went no further? Was its fate sealed with mass closures of branch lines and rural services in the 1960s?

 

[hexagon789]

I was reading about recent developments in battery technology for rail when I came across this fascinating article about a 1950s experiment with a Battery MU in Scotland: https://www.railscot.co.uk/articles...BMU:_Notes_on_the_Battery_Railcar_Experiment/

Running a BMU service on a 43-mile branch line was nothing if not ambitious. I was struck by the weight of the batteries required - 17 tons!

I was wondering if any of the many expert and highly knowledgeable contributors to this forum knew why this experiment went no further? Was its fate sealed with mass closures of branch lines and rural services in the 1960s?

The project was expensive, particularly the cost of the chargers against only one unit. The original batteries weren't replaced by a lighter note efficient type but they had a propensity to catch fire and the unit was thus often substituted by a conventional railcar for much of its later life. The closure of the Ballater Line in 1966 also meant there was no work for it anymore without installing more expensive charging equipment. There were few other lines suitable for it and I think it would be fair to say the technology was still relatively privative - the unit would be 'plugged-in' at both ends to top up the batteries as well as being fully charged overnight rather than being able to run a full days work without being charged up.

The actual unit does survive though, it entered departmental service and was later preserved, funnily enough on the re-opened heritage section of the very line it ran on - The Royal Deeside line to Ballater.

 

[theblackwatch]

The actual unit does survive though, it entered departmental service and was later preserved, funnily enough on the re-opened heritage section of the very line it ran on - The Royal Deeside line to Ballater.

Prior to its move to Deeside, the unit operated on the East Lancs Railway for a while. It could manage a Bury to Rawtenstall return, but I've no idea what the charging regime they had there was.

 

[Swanley 59]

The project was expensive, particularly the cost of the chargers against only one unit. The original batteries weren't replaced by a lighter note efficient type but they had a propensity to catch fire and the unit was thus often substituted by a conventional railcar for much of its later life. The closure of the Ballater Line in 1966 also meant there was no work for it anymore without installing more expensive charging equipment. There were few other lines suitable for it and I think it would be fair to say the technology was still relatively privative - the unit would be 'plugged-in' at both ends to top up the batteries as well as being fully charged overnight rather than being able to run a full days work without being charged up.

The actual unit does survive though, it entered departmental service and was later preserved, funnily enough on the re-opened heritage section of the very line it ran on - The Royal Deeside line to Ballater.

Thank you for the very thorough explanation. I can see why the cost of the charging equipment, not to mention the propensity of the batteries to catch fire would doom the battery railcar to being a "good idea ahead of its time."

I wonder if the preserved unit will ever run again with updated battery tech?

 

[hexagon789]

Prior to its move to Deeside, the unit operated on the East Lancs Railway for a while. It could manage a Bury to Rawtenstall return, but I've no idea what the charging regime they had there was.

Portable charging equipment. On the Deeside it has never worked under its own power, the cost of restoring the power equipment was decided to be prohibitive and it is used as hauled stock.

I wonder if the preserved unit will ever run again with updated battery tech?

Perhaps if they obtained a lottery grant or similar, or a large donation but without those it's very unlikely I'd say, especially in the present climate.

 

[30907]

Thank you for the very thorough explanation. I can see why the cost of the charging equipment, not to mention the propensity of the batteries to catch fire would doom the battery railcar to being a "good idea ahead of its time."

OT, but DB made good use of battery railcars - mainly IIRC in the flatter north. Might be worth a Google?s

 

[Gloster]

There is also information on it on the railcar.co.uk site under Types. (Sorry, I can’t do a link.)

 

[Swanley 59]

There is also information on it on the railcar.co.uk site under Types. (Sorry, I can’t do a link.)

Thanks - just found it. https://railcar.co.uk/type/battery-multiple-unit/summary

== Doublepost prevention - post automatically merged: 26 Apr 2021 ==

OT, but DB made good use of battery railcars - mainly IIRC in the flatter north. Might be worth a Google?s

Will do - thanks. It's always interesting to see how the railways in other countries overcome problems that often seem insurmountable from a British perspective

 

[doorhanger93]

Running a BMU service on a 43-mile branch line was nothing if not ambitious. I was struck by the weight of the batteries required - 17 tons!

It's better with modern tech, but there's still limits; someone suggested battery units going "1000km at 300km/h" in another thread - doing the maths on that indicates 50-100 tonnes of advanced lithium ion!

 

[Swanley 59]

Thanks doorhanger93. Hypothetically speaking, would the 1950s BMU retrofitted with modern battery tech have enough energy to do the Aberdeen - Ballater round-trip on a single charge without the kit exceeding 17 tons?

 

[doorhanger93]

Thanks doorhanger93. Hypothetically speaking, would the 1950s BMU retrofitted with modern battery tech have enough energy to do the Aberdeen - Ballater round-trip on a single charge without the kit exceeding 17 tons?

At a stated voltage of 440V and capacity of 1070Ah, now, there's battery management that can't quite be predicted, but that should be around 470kWh, and with advanced Li-ions that should be about 3 metric tonnes and change, also 3 long tons and change, which is quite an improvement! Now, it mentions charging stations at both ends, but considering the line climbs ~200 meters, with modern regenerative braking, I'd imagine you wouldn't actually need twice that capacity for a round-trip without charging at one end, since you could get some of the energy back, let alone obviously not needing much throttle on the way back down, which the old BMU would have also benefited from. At a guess, 4-5 tonnes of Li-ion might do it for the round trip.

 

[Taunton]

The battery set seemed to work quite well, especially as the outward trip was 45 miles wholly uphill, and I don't feel we have advanced that much in the technology in the intervening more than 60 years - in fact it seems to show that all the stuff about battery power advances is pretty much bionic duckweed - Tesla excepted.

The experiment was joint between BR and the local electricity board, which uniquely in the UK had a large hydro-electric capacity that was somewhat underused. The board did the electric side, but were keen to do a deal which suited them commercially, they appeared to want to overcharge for the power supply, and when called out on this started to lose interest. BR likewise looked at actual running costs, plus depreciation of the fixed installations, and diesel units, even then, were notably cheaper all round, and far more flexible. It's a good example that if the greenwash is taken out of the equation, battery power had, and has, a long way to go.

I remember in 1971 when at university we were all shown a pure battery bus which was on trial in Edinburgh. Again, 50 years on and notably little progress has been made compared to all the hoopla and hype surrounding any attempt in this area, many of which seem to fall by the wayside.

 

[doorhanger93]

I remember in 1971 when at university we were all shown a pure battery bus which was on trial in Edinburgh. Again, 50 years on and notably little progress has been made compared to all the hoopla and hype surrounding any attempt in this area, many of which seem to fall by the wayside.

The battery hype forgets that the electric bus predates, and has always been superior to, the motor bus. So long as you put up the trolley wires

 

[Master Cutler]

If the battery technology used was based on readily available admiralty submarine designs of the time, which were ample for constant duty applications propelling water craft, the irregular loads involved in locomotive traction would probably over stress the power delivery and could substantially reduce efficiently.

 

[Taunton]

One of the seeming constants of the battery industry is forever overstating their capability. You only have to look at some recent RAIB reports of train strandings where the holdover time of the emergency lighting, the PA, etc is constantly less than supposedly it should achieve, and comes with load shedding of what are key aspects of being stuck in a train, like suspending toilet flushing, which never seems to be in the original spec.

 

[mike57]

Its interesting that they went for Lead acid cells rather than the more robust Nickel Iron, weight wise they would have been similar. (Based on currently available nickel iron cells they would have weighed in at around 20t) Also the Irish Railways had a Drumm battery railcar in the 30's which seemed to serve its purpose. I wonder if the SR ever considered anything similar with a 3rd rail pick up/battery, I know the motor luggage vans came later with a battery capability but reading contemporary reports they didnt work that well.

Battery technology seems to have a tendancy to take the best case instead of the worst case, in order to promote it. I had to review a battery backup design (Not rail related) at work some months ago, and I pointed out that the calculations used the optimum discharge rate, which we would not acheive, and new cells together with a perfect charging regime. When you factored these in together with a margin for the things you had overlooked you nearly doubled the capacity you needed.

 

[Taunton]

The Southern MLVs seem to have only been expected to shunt the 200 yards off the 3rd rail to alongside the ship at Dover.

I think your experience with battery suppliers/designers is a typical example.

 

[OVS Flatbottom]

Its interesting that they went for Lead acid cells rather than the more robust Nickel Iron, weight wise they would have been similar. (Based on currently available nickel iron cells they would have weighed in at around 20t) Also the Irish Railways had a Drumm battery railcar in the 30's which seemed to serve its purpose. I wonder if the SR ever considered anything similar with a 3rd rail pick up/battery, I know the motor luggage vans came later with a battery capability but reading contemporary reports they didnt work that well.

The Drumm trains actually had nickel-zinc batteries. The first batch of two two-car articulated sets was introduced in 1932 and a second batch, also of two, in 1939. All of them were withdrawn as battery stock in 1949 because the batteries needed renewal (presumably this only applied to the older sets, but it mustn't have been considered worth continuing with a reduced fleet); most or all then got converted to hauled stock. They proved useful during coal shortages in WWII and early 1947 (because they could run on indigenous hydroelectricity), but I've seen it suggested that the Great Southern would have been better off emulating the GNR(I) and County Donegal by investing in diesel railcars instead. (The GSR did have a handful of Drewry petrol railcars on both broad and narrow gauges, but they weren't very successful; one of the broad-gauge cars was rebuilt into a proof of concept for the Drumm trains.)

(Edited to correct the numbers of sets - there were only four in total)

 

[mike57]

The Drumm trains actually had nickel-zinc batteries. The first batch of four two-car articulated sets was introduced in 1932 and a second batch, also of four, in 1939. All of them were withdrawn as battery stock in 1949 because the batteries needed renewal

The Nickel-zinc battery technology has problems with the electrodes changing shape during charging, but 15/10 years as a battery life seems reasonable to me, reading a few articles it seems like they were used pretty intensively. I wonder why the technology wasn't developed. Nickel, zinc and an alkaline electrolyte would not present problems with disposal/pollution, unlike lead or cadmium or some of the things in Lithium batteries. Nickel - Iron batteries will last much longer, I have read of Nickel-Iron batteries remaining serviceable after 80+ years if the electrolyte is replaced.

 

[Taunton]

The Drumm trains ... They proved useful during coal shortages in WWII and early 1947 (because they could run on indigenous hydroelectricity)

Unfortunately the hydro scheme was on the other side of the country (Shannon/Limerick) to where the Drumm sets were deployed (Dublin-Bray), and there was no modern style ultra-high voltage grid. Dublin was dependent on its coal-fired power stations, and suffered extensive electricity shortages and power cuts, as described by John Betjeman when he was press attache at the British Embassy in Dublin during the war. I don't know how the Drumm sets got through this. The hydro scheme was also impacted itself in the war as it had been built with German components from Siemens, where further units and spares were blockaded, so output fell.

 

[hexagon789]

The battery set seemed to work quite well, especially as the outward trip was 45 miles wholly uphill, and I don't feel we have advanced that much in the technology in the intervening more than 60 years - in fact it seems to show that all the stuff about battery power advances is pretty much bionic duckweed - Tesla excepted.

Indeed but battery discharge was felt to be a little on the high side during climbing and there was no recuperation braking for use in descending on the return trip which even then could have recovered as much as 20% of the lost energy in braking on the descent back.

The Drumm trains actually had nickel-zinc batteries. The first batch of four two-car articulated sets was introduced in 1932 and a second batch, also of four, in 1939. All of them were withdrawn as battery stock in 1949 because the batteries needed renewal (presumably this only applied to the older sets, but it mustn't have been considered worth continuing with a reduced fleet); most or all then got converted to hauled stock. They proved useful during coal shortages in WWII and early 1947 (because they could run on indigenous hydroelectricity), but I've seen it suggested that the Great Southern would have been better off emulating the GNR(I) and County Donegal by investing in diesel railcars instead. (The GSR did have a handful of Drewry petrol railcars on both broad and narrow gauges, but they weren't very successful; one of the broad-gauge cars was rebuilt into a proof of concept for the Drumm trains.)

After successful experiment, arguably more so than the BR/Ballater Line one, but not perpetuated probably because of a lack of money in the late-1940s. They were converted to hauled stock iirc and lasted as such into the 1950s.

 

[OVS Flatbottom]

Unfortunately the hydro scheme was on the other side of the country (Shannon/Limerick) to where the Drumm sets were deployed (Dublin-Bray), and there was no modern style ultra-high voltage grid. Dublin was dependent on its coal-fired power stations, and suffered extensive electricity shortages and power cuts, as described by John Betjeman when he was press attache at the British Embassy in Dublin during the war. I don't know how the Drumm sets got through this. The hydro scheme was also impacted itself in the war as it had been built with German components from Siemens, where further units and spares were blockaded, so output fell.

There was definitely a connection sufficient for the purposes of supplying the Drumm trains (it wouldn't have made sense to build the Shannon scheme without a connection to Dublin, given the low levels of demand in most of the country at the time), albeit not a grid as such and not ultra-high-voltage. This map shows that there were twin 110 kV lines from Ardnacrusha on the Shannon to Dublin in 1929, plus one to Cork, with 38 kV to the other larger towns. The Liffey hydro scheme also came on line in 1943.

The Drumm sets (and, I think, the remaining trams) were disrupted for a while due to low water levels in the Shannon during a drought late in the war (summer 1944?), which suggests that hydroelectricity was providing a significant proportion of the power. (In ordinary times, of course, the coal-fired station - only one at the time, I think - in Dublin could pick up the slack in such circumstances.) I don't know whether Betjeman was referring to this or similar periods when he talked about power cuts; it's also possible that there was some degree of load shedding and the Drumm recharging stations were a higher priority than residential loads, but I don't know how feasible that was with 1940s technology. (There was rationing of power from 1942, according to page 106 of this, but I've never read that the trains were mothballed entirely during this time, except in the low-water periods, though I think there may have been cuts to off-peak services).

I'm not actually sure the Drumm trains would have lasted as long as they did without the war and the 1947 coal shortage (which was even more disruptive to steam traction in Ireland), though @hexagon789 is probably right that a shortage of cash contributed to their demise.

 

[Ashley Hill]

There was also the class 97/7 battery electric units converted from class 501 units.

 

[Taunton]

Indeed but battery discharge was felt to be a little on the high side during climbing and there was no recuperation braking for use in descending on the return trip which even then could have recovered as much as 20% of the lost energy in braking on the descent back.

Yes, it really was a shame it wasn't electrified with regeneration. It was run with two trains, the other one diesel, which passed halfway, and the one descending could have readily aided the opposite one. If there was a water tank underneath like on the Lynmouth funicular filled at the top end to make it heavier, the whole thing could have run by perpetual motion.

I think I should put a here.

 

[hexagon789]

Yes, it really was a shame it wasn't electrified with regeneration. It was run with two trains, the other one diesel, which passed halfway, and the one descending could have readily aided the opposite one. If there was a water tank underneath like on the Lynmouth funicular filled at the top end to make it heavier, the whole thing could have run by perpetual motion.

I think I should put a here.

They seemed to miss a trick there with not equipping the units with a regenerative brake. From memory the six services each way generally split 2 battery and 4 diesel each way.

 

[Bevan Price]

The Nickel-zinc battery technology has problems with the electrodes changing shape during charging, but 15/10 years as a battery life seems reasonable to me, reading a few articles it seems like they were used pretty intensively. I wonder why the technology wasn't developed. Nickel, zinc and an alkaline electrolyte would not present problems with disposal/pollution, unlike lead or cadmium or some of the things in Lithium batteries. Nickel - Iron batteries will last much longer, I have read of Nickel-Iron batteries remaining serviceable after 80+ years if the electrolyte is replaced.

During recharging. zinc does not tend to form nice even coatings on the electrodes - it tends to produce loose (spiky, or dendritic) particles which can then partially short-circuit the inside of batteries, leading to a gradual loss of capacity. That is why attempts to recharge traditional zinc/manganese dioxide batteries were mostly a waste of time/energy.

 

[mike57]

During recharging. zinc does not tend to form nice even coatings on the electrodes - it tends to produce loose (spiky, or dendritic) particles which can then partially short-circuit the inside of batteries, leading to a gradual loss of capacity. That is why attempts to recharge traditional zinc/manganese dioxide batteries were mostly a waste of time/energy.

A bit off topic, but I wonder if with the benefit of modern technology/knowledge it would be possible to eliminate or mitigate the zinc deposition issues during charging. As a battery system for large traction/storage batteries it seems ideal in other ways, relatively innocuous and readily available materials, lighter than Lead acid, and less tempremental than Lithium. Wouldnt replace Lithium at the smaller end, but would have applications in the traction and off grid market. You can now buy 'Edison' (Nickel Iron) batteries from the far east in capacities up to 1000Ah or more, but they suffer from the limit on discharge current which the Drumm battery overcomes. The US patent was filed in 1934, makes interesting reading if you are into that sort of thing.

 

[dallan84]

Prior to its move to Deeside, the unit operated on the East Lancs Railway for a while. It could manage a Bury to Rawtenstall return, but I've no idea what the charging regime they had there was.

ELR built a single phase 230v charger which was installed in the guards van - it was actually bolted to the floor, but took a standard 230v 32 amp mains connection so could plug in to a shore supply.
It charged at a fairly low charge rate over several days, but put enough charge into the batteries to then do a day's running on the line.

When the unit went south to BR Research after the line closed, one of the charging plants (the Aberdeen one?) went south with it and was installed in the shed at Mickelover. What happened to that charger after the unit was sold from BR in the 1980s doesn't seem to be recorded. It was operational at Bradford Hammerton Street as well (after it was sold by BR, but before it moved to the East Lancs) but no idea what charging equipment was in use then.

Thank you for the very thorough explanation. I can see why the cost of the charging equipment, not to mention the propensity of the batteries to catch fire would doom the battery railcar to being a "good idea ahead of its time."

I wonder if the preserved unit will ever run again with updated battery tech?

The propensity of the (2nd set) of batteries to catch fire was, at least in part, down to some experiments that BR were running at the time to see if the unit could be operated recharging at only one end of the line, to see this would improve the economics of the operation. Unfortunately these tests led to the batteries becoming over-discharged and the small battery fire resulted. The experiments seem to have been abandoned at that point, and there's nothing in the archives that suggests there was any further serious battery fires during its use with the research department.

 

[Bevan Price]

A bit off topic, but I wonder if with the benefit of modern technology/knowledge it would be possible to eliminate or mitigate the zinc deposition issues during charging. As a battery system for large traction/storage batteries it seems ideal in other ways, relatively innocuous and readily available materials, lighter than Lead acid, and less tempremental than Lithium. Wouldnt replace Lithium at the smaller end, but would have applications in the traction and off grid market. You can now buy 'Edison' (Nickel Iron) batteries from the far east in capacities up to 1000Ah or more, but they suffer from the limit on discharge current which the Drumm battery overcomes. The US patent was filed in 1934, makes interesting reading if you are into that sort of thing.

Not sure about this, but very slow recharging might produce better deposition of zinc - but recharge times are likely to be impracticably long.
I have a so-called intelligent recharger which claims it can recharge zinc-based batteries, but the results have never been worth the effort.