GG1

[Supermicha]

Its all right. The most common reason is that of dammage. In germany, engines can drive with the front panto up when:

- two engines are used, so that the wire will not become so hot (the second engine must have up its rear panto)
- the car after the engines has loaded automobiles or petrochemical products on which sparks from the panto can make dammage or fire.

QUOTE: heard another rule about the pentograph, that during freezing rain and sleet both graphs must be up so the leading one cleans the wire.

Also that is (or was) right. Older engines, which have pantos with single contact shoes could have problems with getting enough constant voltage when the wire is iced. So all two pantos must be lift up, to warrant a good electrical pickup.modern engines with double, triple or quad contact shoes does not need that.

Its nice to see an electric engine during night, when the wire is iced and the sparks make the night to day.

Something about the wheel arrangement in europe:

1 - non driven axle in the main frame
1` - non driven axle in a seperate frame (single axle truck)
2 - two non driven axles in the main frame
2` - two non driven axles in a seperate frame (seperate truck)
A - one driven axle in the main frame
B - two connected driven axles in the main frame
A´ - a driven axle in a seperate frame or truck
B´ - two connected driven axles in a seperate frame or truck
Bo - two single driven (not connected) wheels in the same frame or truck

A Challenger is a 2´ C´ C´ 2´ engine

A GG1 is a 2´ Co Co 2´engine

The DD40AX is a Do Do engine and so on

And, at last, a hard example:

A kind of german mallard engines had the wheel arrangment B´ B n 4 v

B´ - the first two wheels are driven but in a seperate truck
B - the other two wheels are in the main frame
n - (Naßdampf) wet steam engine
4 - 4 cylinders
v - (Verbundtriebwerk) connected engine (that means the 4 cylinders are connected)


Micha

[Anonymous]

got some pic of a PRR GG1 in Dallas tx RR mueseum also
UP 4018 BIGBOY[8D][8D][8D]

[CSSHEGEWISCH]

PRR did not buy the entire ex-GN fleet. They purchased only eight box-cabs (one for spare parts) which became the FF-2's. One of the W-1's went to GE for the failed coal-fired gas-turbine experiment and everything else was scrapped.

[daveklepper]

There was more than one purchased . Dave Klepper

[kenneo]

QUOTE: Originally posted by daveklepper

I think they had more than one of the ex-GN units. If I remember correctly (from an old issue of TRAINS, of course), they bought the entire ex-Great Northern fleet! Not that all were ever put into service, and at least one was held as a source of spare parts. But they did have more than one in service, at least initially, and they were only used as helpers if my memory is correct. I think they had sleeve bearings, not roller bearings. Dave Klepper

One went to the UP for its coal turbin project. The number 5018 wants to come to mind, but I certainly am not going to bet on that being correct.

[daveklepper]

I think they had more than one of the ex-GN units. If I remember correctly (from an old issue of TRAINS, of course), they bought the entire ex-Great Northern fleet! Not that all were ever put into service, and at least one was held as a source of spare parts. But they did have more than one in service, at least initially, and they were only used as helpers if my memory is correct. I think they had sleeve bearings, not roller bearings. Dave Klepper

[Rick Gates]

All of the previous reasons I have read have merritt. Rear pans were raised ( as far as us hogheads were concerned) because that was the order of the RR. For example: page 13 of the CT290 Electrical Operating Instructions Manual for the Pnennsyvania RR, under the heading of Pantographs states: "3. Under normal operation of single unit engines, rear pantograph shall be up on each engine except class E-44, which must have the leading pantograph up. Adjacent pantographs of coupled engines should not be up when it can be avoided. The number of electrical engines coupled and in service will be governed as follows: 2-4 engines 0 restrictions--5 50mph---6 not exceed 35mph ----over 6 are prohibited." Only a double pantograph train order may be issued in time of sleet or freezing rain. I miss those drafty G-s!

[jeremygharrison]

QUOTE: Originally posted by Oliver Trzok

QUOTE: Originally posted by 440cuin

That "European" system is a better system then ours, it defines more accurately, I forget what it is called. I believe even more accurate is a GG1 is 2'C-C2' or am I talking about another system all together? But even in parts of Europe they use other even more wierd systems. (did every factory use its own system??) The Whyte system realy only works on conventional steam engines. A challenger is not the same as a GG1 but I have to look it up to see the difference. The second set of drivers is rigid with the frame and boiler, not a seperate truck.

[#dots] (I wanted to put the one with the sign "off topic" here, but it's frowning, and I don't think there's anything here to frown about...)

Here in Europe the system is a little more elaborate. And I'm definitely not the person who knows it all, but I know some basics.
A GP40 for instance would be a Bo'-Bo' (the little o's should actually be raised a little, to the level of the apostroph, but I don't know how to do that on the keyboard) - meaning two two-axle trucks (B+B), and the little "o" meaning that each axle has its separate traction motor. Some (majority of?) older French electrics (not sure about the diesels) had one traction motor per truck, so a four-axle two-truck locomotive would be designated B'-B'.
I'm not sure about the diesel-hydraulics, but logically they'd also be B'-B', C'-C' etc. And I think the apostroph stands for a truck (steam engines too) that rotates/swiwels in relation to the rest of the locomotive.
So a Pacific type steamer (4-6-0) would be 2'-C-1', but I don't know abot the Challenger (4-6-6-4) - is it a 2'-C'-C-2' or a 2'-C-C-2'?

[zzz], you say? I can't blame you.

Regards,
Oliver

The 'standard' European system (started, I believe, in Germany, now generally adopted) isn't perfectly standard... but the basics are - it's based on axles, non powered indicated by numbers, powered axles by letters (upper case), with apostrophes to designate trucks (i.e. axles not in the main frame), a lower case 'o' to indicate seperately driven, parentheses (i.e. '(' & ')' to group axles in a truck together, and no hyphens. Less standard elements are underscoring to indicate powered axles in seperate frames mechanically coupled together (if you can follow that), and a plus sign '+' to indicate seperate vehicles (permanently coupled - most often used for railcar sets).
And sometimes extra letters (and numbers) are tacked on the end to let you specify things like whether it's a four cylinder compound superheated rack tank, or a diesel electric with AC/DC transmision - but that's going a bit too far [;)]

Exact positioning of apostrophes and 'o's is one of the variations...

So, to give some examples:
B - basic four wheel loco (0-4-0 in Whyte)
2'C 1' - a normal Pacific (4-6-2)
2' 2' - a standard car on two four wheel trucks
Bo' Bo' and Co' Co' are the normal American diesels (EMD GPs and SDs, etc.), but an EMD 'E' type is (A1A)'(A1A)' - and a three section FT 'locomotive' is a Bo'Bo' + Bo'Bo' + Bo'Bo'

So a Challenger is a (2' C)' C 2' and a GG1 (2' C)' (C 2')' - if I understand them correctly.

And a three truck Shay B'B'B' (assuming four wheel trucks)

So it's capable of describing pretty well anything, once you get used to it..

But as 440cuin stated, in past times othe systems were used, varying between countries - the most common being 'Whyte but counting axles', and just giving numbers of powered and total axles.

Jeremy

[marxalot]

Hey, thanks for all the good info. I'm looking at that New Brunswick
Railroad Museum site for the GG1 forum. Thanks again. Somehow
Trains has an old e-mail address for me and I never did receive a
notification at my more active address. I thought I HAD asked the
ultimate dumb question![:D]

[Anonymous]

QUOTE: Originally posted by kenneo

QUOTE: Originally posted by trainheartedguy

What? no comment on my pic?

[soapbox][tup][tup][tup][tup][:-^][wow]

Good to see one of the old girls again. ...

Thank you Kenneo

[tree68]

I've always associated pure numbers with steam - ie, a 4-4-4-4 will be steam, with nothing denoting powered axles except convention (ie, usually the first and last are not powered, but not always.) On the other hand, letters denote locos with electric propulsion (be they diesel-electric or electric), with any numbers denoting unpowered trucks. That makes it a 4-B-B-4. Then there are those like the U50B, denoted as B-B+B-B, all axles powered. I have seen the Bo-Bo type notation as well, but it's not usually seen in the US trade or model press.

[Anonymous]

QUOTE: Originally posted by oltmannd
[3. Except for the Metroliner service, 100 mph for a GG1 was pretty rare. In fact, the speed limit for them on the NEC was only 80. Fastest I ever clocked one was in the low 90s thru Northeast Philly on a NY-PHL clocker.

Keeping the GG1s below 100 was deliberate on the part of the Pennsy. PRR did some testing (they seem to have tested everything) and had a GG1 with 100 mph gearing and another with 90 mph gearing try to keep the same schedule from DC to NY. They found to everyone's surprise that the 90 mph geared locomotive could actually keep a faster schedule. This was due to the numerous station stops and many restricted speed curves on the corridor. The 90 mph geared GG1 could out accelerate its counterpart pulling an identical train.

[Anonymous]

QUOTE: Originally posted by 440cuin

That "European" system is a better system then ours, it defines more accurately, I forget what it is called. I believe even more accurate is a GG1 is 2'C-C2' or am I talking about another system all together? But even in parts of Europe they use other even more wierd systems. (did every factory use its own system??) The Whyte system realy only works on conventional steam engines. A challenger is not the same as a GG1 but I have to look it up to see the difference. The second set of drivers is rigid with the frame and boiler, not a seperate truck.

[#dots]
(I wanted to put the one with the sign "off topic" here, but it's frowning, and I don't think there's anything here to frown about...)

Here in Europe the system is a little more elaborate. And I'm definitely not the person who knows it all, but I know some basics.
A GP40 for instance would be a Bo'-Bo' (the little o's should actually be raised a little, to the level of the apostroph, but I don't know how to do that on the keyboard) - meaning two two-axle trucks (B+B), and the little "o" meaning that each axle has its separate traction motor. Some (majority of?) older French electrics (not sure about the diesels) had one traction motor per truck, so a four-axle two-truck locomotive would be designated B'-B'.
I'm not sure about the diesel-hydraulics, but logically they'd also be B'-B', C'-C' etc. And I think the apostroph stands for a truck (steam engines too) that rotates/swiwels in relation to the rest of the locomotive.
So a Pacific type steamer (4-6-2) would be 2'-C-1', but I don't know about the Challenger (4-6-6-4) - is it a 2'-C'-C-2' or a 2'-C-C-2'?

[zzz], you say? I can't blame you.

Regards,
Oliver

[kenneo]

QUOTE: Originally posted by 440cuin

That "European" system is a better system then ours, it defines more accurately, I forget what it is called. I believe even more accurate is a GG1 is 2'C-C2' or am I talking about another system all together? But even in parts of Europe they use other even more wierd systems. (did every factory use its own system??) The Whyte system realy only works on conventional steam engines. A challenger is not the same as a GG1 but I have to look it up to see the difference. The second set of drivers is rigid with the frame and boiler, not a seperate truck.

Do not misunderstand my little "smilee". 4-6-6-4 is 4-6-6-4 whether or not it is a GG1 of a Challanger.

CSSHEGEWISCH is correct in his wheel arrangement note. And I made a goof, but my point was not a critisim of him. Just a starting point. Sorry, sir.[:(][:(][:(]

As a side note, a P5B (in pairs) would be something to see on the NEC. Replace the EXCELLA power cars with one of these on each end, (modern electricals and gearing, of course) and AMCLACK would have one fast train.

And if it were not for bad spelling, I would not be spelling at all tonight.

4-6-6-4 (E and S) and 4-6-4 (E and S) forever. (Challanger, Hudson, GG1 and P5)

[TH&B]

That "European" system is a better system then ours, it defines more accurately, I forget what it is called. I believe even more accurate is a GG1 is 2'C-C2' or am I talking about another system all together? But even in parts of Europe they use other even more wierd systems. (did every factory use its own system??) The Whyte system realy only works on conventional steam engines. A challenger is not the same as a GG1 but I have to look it up to see the difference. The second set of drivers is rigid with the frame and boiler, not a seperate truck.

[kenneo]

QUOTE: Originally posted by CSSHEGEWISCH

Minor corrections on wheel arrangement: axles are counted, numbers are unpowered, letters are powered, thus:
GG1 - 2-C+C-2
P5A - 2-C-2, P5B - B-C-B
Little Joe - 2-D+D-2 (same on a Centipede)
Bi-Polar - 1-B+D+D+B-1
W-1 - B-D-D-B

You be using the European system. They count axels. Here in Norto Americano, we count wheels. Ever check the builders plate on a - say - GP9? Under wheel arrangement is reads "0-4-4-0". Us folks, however, would say B-B. C-C, senior.

It really doesn't matter much how we put it so long as we know what we are talking about. And I understand you. Just to throw a little curve, but look at the various P5's. You can have either a 4-6-4 (P5A) or a 0-4-6-4-0 (P5B) if you use the diesel version of the Whyte system.

4-6-6-4s (both Challengers and GG1's) forever!

[kenneo]

QUOTE: Originally posted by trainheartedguy

What? no comment on my pic?

[soapbox][tup][tup][tup][tup][:-^][wow]

Good to see one of the old girls again. Too bad that GE didn't put new equipment in them instead of building those [censored] looking E's that are now going the way of all old locomotives. RIP.

[Anonymous]

What? no comment on my pic?

[CSSHEGEWISCH]

All GN electrics were motor-generator sets. I believe that the VGN EL-2B's were also motor-generators. Both roads were energized at 11,000 volts AC. Current was supplied to a large AC motor which shared a shaft with a DC generator. The DC generator then supplied current to the DC traction motors. Regenerative braking was also possible with this arrangement.

[jchnhtfd]

QUOTE: Originally posted by talbanese

Jamie,

Thanks for the good info. I can easily see the pans on the Amtrak Loco. It thought they had springs. This is happening at slow speeds as trains are exiting and entering the station from the south, about 500 feet from the start of the platforms. It happens at the same locations. It real cool when its dark out!!

As Kenneo said, may be track switches there, or possibly an insulated break in the overhead (sections of overhead are insulated from each other so a fault in one area doesn't short out the whole NEC, which would be embarrassing...[:(]). Either the pantograph is forced out of contact by a misalignment (vertically) between the diverging and straight sections of overhead, or moves out of contact and then back as it goes past the insulating gap (the gap is long enough so that the pan contacts can't bridge it) (but not so long that there is any significant possibility of stopping on it![:D]). If that happens and the thing is drawing current, she's going to arc every time!

[oltmannd]

QUOTE: Originally posted by daveklepper

The GG1 had all axels powered, including the front and rear four-wheel trucks, so you had a total of ten motors as compared with six for the E-60's and four for the AEM7's. I'm unsure of the exact horsepower or KW or amperage ratings, but I syspect the four motors on the two four-wheel trucks were about the same rating as the typical modern diesel-electrics motor, or about the same as each of the six on an E-60, but the six on the twelve "drive wheels", larger diameter, were probably considerably larger and obviously had larger cooling surfaces than the six under the E-60. So, with a lot of powered wheels, and all the weight providing adhesion for traction, and a very efficient springing system that kept slippage down without much in the way of sophisticated anti-slip control, you had a winner . Remember that this was a locomotive that could handle a passenger train at sustained 100mph speeds and still also hall a 75-100-car freight . I would say it was equivalent to three E-6 2000 HP diesels both in terms of speed and pulling power. I'm disscussing the 100mph geared variety, the "freight" GG1's were geared for 90 mph top speed. Yet, all in all it really wasn't terrifically different than the New Haven's EP-4's! The GG1's finast hour in my book is when they took over the ailing Metroliner MU cars that could not keep the schedule under their own power and maintained Metroliner schedules pulling the Metroliner mu cars, motors and all, cas trail cars. Dave Klepper

Dave-

You need to take off the rearward facing rose colored glasses![:)] I like GG1s too, but they weren't the "second coming"!

1. An E60 could blow the doors off a GG1. This is not a knock on the GG1. It's just that the E60 was a bigger, more capable locomotive built with newer technology. An E60 can do 6000 cont. HP vs. 4600 for a GG1. Both can do a bit more than their rating for a short time. You CAN say the GG1 rode better at speed and was, in general, more reliable (but the GG1s weren't quite as reliable as you might think...)

2. A 6 car Metroliner could blow the doors off a GG1 plus gen car plus 3 Amfleet. Each pair of Metroliner cars was rated at 2400 HP continuous. They tested at 160+mph. Amtrak had to lengthen the Metroliner schedules to 3+ hours from 2:40 when they used the Gs. Even the Congressionals at their best only held down a 3:20 schedule. Again, you CAN say that the GG1 "Metroliners" rode better and were more reliable. Reliability and ride quality are what did in the Metroliners, not performance.

3. Except for the Metroliner service, 100 mph for a GG1 was pretty rare. In fact, the speed limit for them on the NEC was only 80. Fastest I ever clocked one was in the low 90s thru Northeast Philly on a NY-PHL clocker.

[TH&B]

Anyone ever heard of the FF2? (1-C+C-1) Both pantographs on this unit had to always be up. Why? I don't know exactly all the details but it had something to do with that inside this big boxcab there was a generater that ran off the AC to create DC for DC traction motors, this was an ex GN electric once used in the rockies, the idea being DC was better for low speed tork. The generater ran at a constant speed set by the frequency at the wire, aparently it was important that the pantograph had constant contact so in case it bounced constant contact was kept by at least one of the two was always touching, both graphs were always up. This engine was used as a helper for frieght, it didn't realy last too long on the PRR. A nice looking unit.

[CSSHEGEWISCH]

Minor corrections on wheel arrangement: axles are counted, numbers are unpowered, letters are powered, thus:
GG1 - 2-C+C-2
P5A - 2-C-2, P5B - B-C-B
Little Joe - 2-D+D-2 (same on a Centipede)
Bi-Polar - 1-B+D+D+B-1
W-1 - B-D-D-B

[Anonymous]

QUOTE: Originally posted by daveklepper

I stand corrected on the pilot truck GG1 motors, yet I do remember reading something about this in an authoritative publication many years ago. Perhaps it was an experimental installation? Can anyone enlighten me?

Perhaps what you are thinking of is the P5B that the Pennsy made. They took one of the P5A locomotives and added motors to the leading and trailing trucks. Thus turning a 4-C-4 into a B-C-B. It was more powerful than the P5A but not enough to bother repeating.

[Anonymous]

QUOTE: Originally posted by daveklepper

I stand corrected on the pilot truck GG1 motors, yet I do remember reading something about this in an authoritative publication many years ago. Perhaps it was an experimental installation? Can anyone enlighten me?

Hi Dave, hi everyone!

No, I won't pretend I could enlighten you or even give you any hard facts, but I think I remember reading somewhere that each of the six driving axles of a GG1 had two traction motors, so there were actually a total of 12 traction motors in each GG1.
Anyway, they were gorgeous machines. [bow]

Have fun!
Oliver

[daveklepper]

I stand corrected on the pilot truck GG1 motors, yet I do remember reading something about this in an authoritative publication many years ago. Perhaps it was an experimental installation? Can anyone enlighten me? Regarding making up time. Remember when both the Silver Meteor and the East Coast Champion had 24 hours schedules Miami - NY? The ACL had a double-track block signalled line and the SAL a single-track CTC (mostly) line. One day I boarded the northbound Silver Meteor at Jacksonville to ride coach to Southern Pines, NC. Three E's on the head-end, forget whether E7's or E8's. Rode the rear round-end observation (coach passengers were allowed to do so on the SAL). One of the secondary trains had been dropped from the schedule, and its express and mail work was transferred to the streamliner, but the schedule had not yet been lengthened from 24 hours. (It was at the next timetable change, and the ACL did the same.) On the straight alignment north of Jacksonville I clocked the mileposts a mile each 36 seconds. That's 100 mph. The brakeman was sitting on the other rear-facing seat. I turned to him and said: "We are going 100 miles per hour!" He replied" "The ICC mandated speed limit on this line is 79 miles per hour, and that is as fast as we are going." I: "But I'm timing the mileposts at a mile each 36 seconds, and that is 100 miles per hour." He simply repeated the same sentence over again. I shut up. I didn't tell anyone, either. At that time the running time for the Silver Meteor was 3:45 from Washington to New York. The regular hourly expresses were 3:55 (including if memory is correct the Colonel and Senator from Boston); the Morning and Afternoon Congressional were 3:25 or 3:30. I don't remember what the running time of the East Coast and West Coast Champions were, and maybe someone can remind me. Washington-NY was GG1 territory, other than the MP54 mu locals (and lots of them), all passenger service was with GG1s. Florida trains, trains to the west diverging a Zoo interlocking, the trains St. Charles (Norfolk Bay) with engine change at Wilmington, the Southerner and through cars for other Southern and C&O trains, even the Jersey Coast commuter locals used GG1's to South Amboy. Then came the Metroliner MU cars. After the Penn Central absorbed the New Haven, GG1's began running through to New Haven. My only GG1 cab ride was on the 75th anniversary of the establishment of the NYNH&H with a friendly railfan engineer (who shall of course be nameless) from New Haven to Penn Station. The only bad thing about the GG1 was that the cab was like a steam locomotive, and not like an "automotive" diesel, and I was told they were cold in winter and hot in summer. But every engineer I ever met liked running them despite the discomfort. Dave Klepper

[kenneo]

Arcing --- are there track switches at that location? I would venture that there are, and the pantographs will arc against the wire at such locations as they pass by the insulators.

GG1's wheel arrangement is 4-C+C-4. The locomotive nomenclature (GG) comes from the PRR nomenclature for a ten-wheeler - Class G. As far as the PRR was concerned, what you had was 2 10-wheelers back to back. The 4-C on each end was a span bolster with an articulated joint and the car body rode on top of the span bolsters. That is where the "+" comes in.
...................................... _____ + ______
Looks something like this ooOOO + OOOoo. The carbody sits on top of the lines.

Hauling ability - Two Points -- First Point - The comments above about the motors and such are esentially correct. What also needs to be factored in is the fact the power source is not carried on-board, but is land based with a (supposed) unlimited ability to put juice to the locomotive. What is being said is, a 4,000 HP (GG1's were rated at 4000HP) diesel can only produce 4,000 HP. Period. I was told once, but have since forgotten, but my memory says the GG1 could, on a short term basis, produce between 8,000 and 12,000 HP which is one of the reasons it could haul a 28 car express and still maintain the schedule. The power station would just keep producing and the locomotive would just keep on using - almost without limit. It would probably take something 6 E-9's to do the same job but at a slower speed - probably 80 MPH. This ability of wire over diesel is why it is still in use in the NEC.

Second Point - Gearing. Gearing. Gearing. The slower you gear for, the more an electric motor will haul. The faster, it will haul less, be more slippery and race with the wind. These two reasons are why a "normal" passenger consist for a streamliner was usually no more than 22 cars and 4 E7, E8 or E9's. With a train such as a "City" geared for 110 MPH, it would take 4 E9's to keep a 100 MPH schedule. Until the FRA put a stop to it, the UP would regularly run the "City of Los Angeles" across Utah and Nevada at 105 MPH where it was posted for 79 to make up time.

Head hurting yet? [:D] A bit more complicated than "make the joint, blow and go".

[Anonymous]

Jamie,

Thanks for the good info. I can easily see the pans on the Amtrak Loco. It thought they had springs. This is happening at slow speeds as trains are exiting and entering the station from the south, about 500 feet from the start of the platforms. It happens at the same locations. It real cool when its dark out!!

[jchnhtfd]

QUOTE: Originally posted by talbanese

QUOTE: Originally posted by jchnhtfd


It is very rare to have both pans up, for the reasons given above. You simply don't need them. That being said, one of the more intriguing problems with high speed electric 'engines' (such as the Acela, or even more, the European high speed trains) is keeping the pantograph in firm enough contact with the overhead to transmit the current. I recall an engineering demonstration run of a TGV, some years ago now, at night. The section of line used has a slight imperfection (you couldn't see it by eye, but it was there!) in the overhead -- and the shower of sparks which resulted when the pantograph it that at about 200 mph could be seen for miles.

I see arcing on the NEC everyday. There are a few high spots (a guess) on the NEC just south of the Wilmington Station. Do the pans adjust at all? Are they set at a fixed height?

There is a lot of vertical travel available in a raised pantograph. Pantographs have springs which are supposed[:)] to hold them against the overhead, together with (usually) some air pressure (some designs use motors to raise or lower). Older designs had just the springs and air -- and depended (like old cars with leaf springs!) on friction in the joints to provide some damping. Newer designs, and all high speed designs, have what amount to shock absorbers in the linkage, to keep them from bouncing around -- and off the overhead[:(]. Where things get interesting is that the overhead deflects with the pressure of the pan on it...[:D] It is pushed up by the pan, so, naturally, it deflects down a bit in front and in back[8)]. Depending on the speed of the train, and the design of the overhead, and the tension on the overhead, it is quite possible to get the whole overhead to produce a nice wave[:o)] -- and if the timing is wrong, the pan may be unable to rise fast enough to keep up with the wave -- at which point you get arcing. Or the lights go out...[xx(]. Can be quite violent! And a very complex problem for the poor designers to try to solve...

The front pan can be raised to knock off snow and ice. Quite an improvement on the early trolleys when, so I have heard, there were occasions on which a mechanic had to ride the top of the trolley knocking the ice off with a broom. Not me, thank you!