Road Trains, Max Loads and other such semi nonsense

[Spencer]

I've recently reconnected to Car Wars, which I played in the 80s when I was a youngster. Discussions with an old friend prompted this thread.

In Australia, the truckers use a rig setup called a Road Train. simply put, this is 2 or 3 full-sized semi trailers hooked to a single heavy hauler tractor. This prompted some discussion on what kind of rules would apply to a Road Train, or for that matter how to build a heavy hauler. I've has some thoughts:

1. Max Load still applies insofar as to calculate top speed.
2. A heavy hauler can use a specific type of huge engine, just like they do IRL. This would have to be custom designed. The advantage would be that the tractor would have plenty of max weight for pulling; the disadvantage would be that such engines would require practically all the spaces available in the tractor. These engines would also be expensive.
3. The first trailer would have to have a hauling dolly and hitch, which would be heavy and be a potential weak point in the system (broken dolly=everything behind it comes uncoupled and crashes). The hitch system would be based on the drawbar and need a heavier load limit; it would also have to have several tires to allow it to function properly.
4. Fuel/PP usage would be a massive limiter. Road Trains would use PP/fuel at (total vehicle weight/total max load) times the rate, rounding up to the nearest PP/gallon.
5. Heavy Haulers could also be used for oversized loads on flatbed trailers.
Thoughts?

[Spencer]

I've some ideas about tandem dollies and drawbar hitches, which would be necessary to hitch 2 semi trailers to each other. I've also come up with a special engine:

Heavy Hauler Engine: 5000 lbs, 20 spaces, 40 DP, max acceleration 2.5 at all speeds, max speed 60 mph due to gearing, max load 120,000. Compatible with platinum catalysts, super conductors, and extra power cells. Not compatible with HD transmission (one is already built in).

Drawbar Hitch: 320 lbs, no spaces, 8 DP, tow capacity 160,000. Trailers hitched to dollies must have a drawbar hitch equipped.

Single Axle Tandem Dolly: Weight 5000 lbs, no spaces available. Requires 4 tires. Can be equipped with any tires; can use fifth Wheel Armor, AWH and Wheel Guards. Wheel Guards may not be retractable. 8 DP. Max tow capacity 80,000. When dolly frame takes damage, each point reduces tow capacity by 10,000 pounds. If towed weight exceeds tow capacity, roll 1d6. Each point causes a 1 in 6 chance of the dolly frame breaking and trailers behind the frame coming loose. If towed weight exceeds towed capacity by more than 50,000, frame breaks. Weight of Tandem Dolly counts towards total load.

Double Axle Tandem Dolly: Weight 8000 lbs, no spaces available. Uses 8 tires. Can be equipped with any tires; can use fifth Wheel Armor, AWH and Wheel Guards. Wheel Guards may not be retractable. 16 DP. Max tow capacity 160,000. When dolly frame takes damage, each point reduces tow capacity by 10,000 pounds. If towed weight exceeds tow capacity, roll 1d6. Each point causes a 1 in 6 chance of the dolly frame breaking and trailers behind the frame coming loose. If towed weight exceeds towed capacity by more than 50,000, frame breaks. Weight of Tandem Dolly counts towards total load.

To use these components, max load rules would be modified this way:
Tractors equipped with Heavy Hauler engines can accelerate so long as max load exceeds total weight divided by 3. Top speed is calculated normally, but max speed cannot exceed 60 mph. Power unit usage is (total weight/max load weight, rounded up) times the normal power unit usage for a given speed. Trucks equipped with Heavy Hauler engines cannot accelerate past max speed.
When moving a road train, move the tractor first, then the lead trailer, then the next trailer, etc. Trailers conform to the unit in front of them. A Road Train cannot back up faster than 2.5 mph.

More will follow as my research continues.

[ckosacranoid]

I would say that a road train would not be able to back up do to the trailer's ability to keep straight.

[Spencer]

I've been thinking about that.
If and only if backing was possible, then keeping a road train straight while backing would be a maneuver with a progressive difficulty, based on the number of articulation points. Each articulation point would add double the difficulty: Backing a trailer would be a D1 maneuver; backing a double would be a D2 + D1, or D3 maneuver; backing a triple would be a D7 maneuver. Success would keep the trailers straight; failing a maneuver roll would cause the trailers to turn randomly. Divide the margin of failure by half; the rear trailer does a random turn of that level, the trailer in front of it does a turn the opposite direction by half that, progressing all of the way to the tractor.
Example: Moe, a novice trucker, backs up a triple. This is a D7 maneuver, so he makes a check at -6, and fails his roll by 4. Move the tractor back 1 square; the front trailer conforms to the move and then gets a D1 turn applied; the middle trailer conforms to that move and then gets a D1 turn in the opposite direction applied; the rear trailer conforms and then gets a D2 turn in the original direction applied. Moe spots the problem and stops, pulling forward and cursing the person who invented triple trailers.
Obviously, driving a double or a triple would require skill as a trucker, just as it does in real life. Only the most experienced drivers would be able to back tandem rigs.

[Spencer]

Obviously, the merit for driving road trains would be based on hauling a respectable load vs. keeping that load safe while hauling. One trailer could be heavily armed while any others could keep most of their spaces and weight available for cargo, allowing a single rig to haul a significant amount of supplies between towns.
Most towns, however, would not permit double and triple rigs to drive on regular streets inside city limits. With that many articulation points, the potential for a road train to accidentally steamroll a parked car or sideswipe a building would be too high.
I'm also giving some thought to pup trailers, as my research indicates that some rigs (B doubles, for example) pair a pup trailer with a full trailer. I'd also like to provide something which would allow the creation of a pup trailer tandem, such as can be seen hauling packages in the United States.

Pup Trailer: a pup trailer can be any trailer type. It is half as long as a full trailer and has half of the spaces available for that trailer type. Pup trailers can mount a 4 space turret, but can only mount 1 due to its shorter length. Pup trailers can be linked into tandem rigs with a tandem dolly. Any rules which apply to a trailer type also apply to the pup variant of that trailer; any space limits on mounting equipment, such as the space limit for flatbed trailers, are also halved.

[Spencer]

I've also given some thought to oversized loads. These would normally be hauled on a flatbed trailer. Oversized loads would be treated like tandem trailers regarding restrictions on road use in town.
Wide loads: Wide loads affect handling just like loads stacked too high. Any load which is more than 1/2" wide is a wide load. For each additional 1/4" or width, add D1 to the hazard of any maneuver. Additionally, wide loads allow flatbeds to exceed space limits on flatbed trailers. Count the total number of squares in the width of the load and divide this by 2, then multiply by 70. This is the maximum number of spaces of cargo allowed for a load of that width. This only applies if the cargo is in one piece; smaller amounts of individual cargo cannot be stacked into a wide load.
Tall loads: Some wide loads are also tall loads. Add 10 spaces to the base stacking limit for flatbeds regarding spaces for each 1/4" of additional width; use this as the base for figuring the stacked cargo hazard. An oversized load which is both tall and wide would apply both hazards.
Example: Moe, our hapless novice trucker, has to haul a massive assembly for a factory. The assembly is 15' wide (1" scale), 15' tall, weighs 120,000 pounds, and takes 110 spaces. Since the load is twice the width of the trailer, the trailer can support up to 140 spaces of cargo; the base for figuring the hazard of stacked cargo is 40 spaces. This piece of cargo is 70 spaces above that limit, so the total turning hazard is D2 (for width of cargo) plus D2 (for height of cargo), or D4 added to every maneuver. Moe doesn't want to drive very fast with this load on the trailer, and he's not going to be able to drive in town without a special permit. Additionally, with a load that heavy, he will have to use a tractor with a heavy hauler engine in it...and he might want to think about getting lead and trail vehicles to warn other drivers about the oversized load that he's going to be hauling.
Tandem trailers cannot be used in combination with oversized loads. Not only is this illegal and damaging to the road, but the driving hazards from each load would apply (If Moe had to drive a double oversized load like that in the previous example, D8 would be added to every maneuver and failure would likely snap one or both of the kingpins).

[43Supporter]

_Road Atlas and Survival Guide Vol. 4_ has similar rules (if far less detailed) for Road Trains. IMSMC: An RT has a second OS power plant in the lead trailer.

Someone in NOVA tried one of these back-when; it failed miserably in practical terms. Someone [cough >:) ] arranged for a barricade of three debris-filled semi-trailers blocking the road just past a hill crest... the result looked like the tractor had been taken out with a Bomb, and the malefactors skated with the trailers, so the guy playing them didn't know his cargo had been boosted until *much* later.

[Spencer]

Well, now...I'll have to pick up a copy of that Road Atlas.
I'm curious, though...are there also rules for pup trailers and oversized loads out there?

[juris]

A super truck PP has more than enough power capacity to haul 2 or more trailers. A sleeper longnose with an x-hvy chassis can still pull another 63,000 lbs. Most trailers weigh about 16,000 lbs empty.

You just need to homebrew a heavy enough hitch.

Probably knock HC down by 1 per extra trailer - otherwise I see nothing wrong with it

[Spencer]

In the second post in this thread I included my proposed drawbar hitch homebrew.

Part of what I was proposing with the heavy hauler power plant was to provide enough weight capacity to pull cargo with 2 full trailers or to power an oversized rig, both of which exist IRL. The prime movers for those real rigs have more powerful engines to handle the extra loads.

I've also started to give some thought to tandem steering axles, another item which is sometimes used for heavy hauling:

Tandem steering axle: $5000 per axle on the trailer, 500 pounds per axle, 1 space per axle. A trailer equipped with tandem steering axles must have tandem steering on every axle, including the front axle if equipped. Tandem steering axles turn when the tractor turns, swinging the end of the trailer the opposite way to prevent jackknifing and allow better cornering. When a rig with tandem steering axles turns, the back end of the trailer swings 1/4" in the opposite direction of the turn at the end of the trailer's maneuver (after lining up the trailer over the kingpin, put a finger on the kingpin dot and pivot the end of the trailer1/4" towards the outside of the turn). Tandem axles reduce the handling cost of maneuvers greater than D1 by 1. Road trains do not require tandem axles on all trailers, but a tralier with tandem axles will not function if hitched behind a trailer without tandem axles.