Talk:Semi-trailer

From Wikipedia, the free encyclopedia

WikiProject Trucks This article is within the scope of WikiProject Trucks,
a WikiProject which aims to improve all articles related to trucks.
??? This article has not yet received a rating on the assessment scale. [FAQ]
??? This article has not yet received an importance rating within truck articles.

This article has not been rated for quality and/or importance yet. Please rate the article and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article.

I'm not sure how much can be added to this article? RfD and move its content to Wiktionary? Xiner 17:40, 4 October 2006 (UTC)

I separated Semi-trailer because people had commented variously at Talk:Semi-trailer truck that it needed a separate entry and that they wanted to add content to such, as some had at that talk page. Some of those comments are months old now, so who knows what will come of them, but that was the idea. ENeville 17:54, 4 October 2006 (UTC)

Contents

[edit] Trailer technology

In answer to all the above;- There are a great number of different types of semi-trailers, a lot of technology and a certain amount of history which needs to be added here but it takes takes time to do the research, gather the necessary illustrations and continue to write the article. If anyone beats me to it, be my guest. Apgeraint 05:07, 13 January 2007 (UTC)

[edit] proposed merge from Turnpike Doubles

The article Turnpike Doubles should be merged somewhere, but I suspect either Semi-trailer truck or Road train may be a better target. Or maybe these three (four with Turnpike Doubles) articles need to be considered together and ensure the right information is in the right one, with proper cross-linking. A turnpike double sounds like a "toy" road train with short trailers and single-axle dollies. --Scott Davis Talk 02:08, 8 February 2007 (UTC)

Probably just ditch that page. The information is covered better in the North America section of Semi-trailer truck IMNSO. A turnpike double is a very specific rig - two ~50' trailers. The Turnpike Doubles page is fairly confused.Toiyabe 19:41, 8 February 2007 (UTC)
Agreed. Should we redirect that page over to Semi-trailer truck? —Cliffb 04:35, 9 February 2007 (UTC)
  • Agreed. What Toiabe said. Greg L (my talk) 01:19, 19 August 2007 (UTC)
Better to fix the link on Interstate 90 (and perhaps expand the text to contain an explanation) and just drop/{{prod}} it - if we were keeping the article it should be named Turnpike double anyway (lower-case 'D', singular instead of plural). --Scott Davis Talk 07:04, 9 February 2007 (UTC)

I wrote the article: "Turnpike Doubles". I agree it is covered, to some extent, in other articles. However, this [Turnpike Doubles] is not an international term. It is a slang term in the United States. It is important to note: that to Drop the "S" at the end of Double(s), would not properly represent the slang term. The colloquial term in the United States is, "Doubles" not "Double". If the article must be internationally ambiguous, then my definition of the USA slang is irrelevant. - Don Corman —Preceding unsigned comment added by 74.65.169.233 (talk) 16 June 2007

Would it be stupid to make a list of differently named road trains in the road train article, as to cover local and international terms for vehicle combinations with more than one (semi)trailer? G®iffen 11:25, 16 June 2007 (UTC)
Don - would one of these trucks be "a turnpike double", "a turnpike doubles", or "a Turnpike Doubles" (plural and case)? I'd also support merging the article and listing names in one of the other articles. --Scott Davis Talk 14:22, 16 June 2007 (UTC)

Scott- I'm not sure that a slang should be a separate article. The actual term used by regulators/operators in USA is "Tandem Trailer Operation" (TTO) A driver might be overheard to say, "I'm hauling doubles to New Jersey tonight", or,"I'm going to be pulling Triples to Chicago", etc. I question the relevancy of my article as more than a footnote, to clarify a colloquial term. - Don

-)Good idea, they should be on the same page. When adding things dont forget about other countries. I am an Australian and we have similar trucks to what is described. One being the 'Road Train' or 'Triple' where trailers are coupled together with dolly's, also there is a 'B Double' where a smaller body trailer (normally 40' odd length with a 24' loadable body {ie. flat top or tautliner}) with a turntable fitted onto the chassis couples to the next trailer, which also can be configured into a 'B Triple' or 'AB Triple'. As a general rule now the smaller body trailer is called an 'A' trailer and the normal 45' trailer is called a 'B' trailer.- Wade from down under. —Preceding unsigned comment added by 122.148.71.147 (talk) 11:39, August 30, 2007 (UTC)

[edit] Battery semi-trailer

A battery propulsion semi-trailer is a semi-trailer that contains the batteries that are used to power an electric truck or bus.

Has anyone ever really built a semitrailer equiped with this many batteries? I'm familiar with the concept of using a smaller one, but I've never seen pictures or heard discussion of one much bigger than a one or two axle thing that could be towed by a much lighter vehicle. If they have, surely it warrants expansion to cover how many batteries, the range, the load capacity, etc. like all the other electric vehicle articles. MrZaiustalk 17:07, 13 March 2007 (UTC)

[edit] Definition of Semi-trailer - comments please

In both this article, Semi-trailer, and the Trailer (vehicle) article, a semi-trailer is defined as a trailer without a front axle. This definitions does not specify the semi-trailer belongs a truck. Most trailers, including small trailers which are commonly towed by smaller vehicles with a tow hitch and are not part of a truck, do not have a front axle. The smaller trailers have one or possibly two axles with wheels in the middle or middle-to-back of the trailer to support the weight of the trailer, but their attachment to the towing vehicle keeps them level. However, both this article and the Semi-trailer section of Trailer (vehicle) are written as if they are only covering semi-trailers for full-size semi-trailer trucks.

Now the question is:
1. Is the definition correct ? Do these article/section need to be expanded to cover additionally small trailers without front axles (not part of trucks)? ... or
2. Should the definition be changed to:

A semi-trailer is a trailer without a front axle in a semi-trailer truck.

I am presently leaning towards the latter (changing the definition as in 2.). Before I make the definition change in the two articles, I will wait at least a week for feedback comments.
H Padleckas 03:14, 13 July 2007 (UTC)

No, I don't think the definition is inadequate. It is general, covering a light trailer on a hitch behind a SUV, as well as heavy freight rigs. What is inadequate is the article, which discusses only equipment appropriate to highway freight operations. It needs a paragraph or even a mere sentence alluding to lightweight semitrailers. Semi-trailer truck doesn't need that sentence, since it is more obviously restricted to heavy haulage. Jim.henderson 05:08, 13 July 2007 (UTC)

I am the person responsible for writing this definition after having compared various driving manuals from the U.K., U.S.A., Canada and France.
Semi is a French or Latin word meaning half, so semi-trailer means half-trailer. In other words, not a full trailer. A full trailer is one that's towed behind a vehicle and rolls along on its own wheels, whereas a semi-trailer has an axle (or axles) at the rear but none at the front since its front end rests on top of the tractive vehicle which supports a considerable proportion of its weight. The following definition, which is in three parts, is perfectly correct. Any trailer which fits the following definition is a semi-trailer irrespective of its size, weight or type of tractive vehicle.
1. "A semi-trailer is a trailer without a front axle." This is the very basic definition and
2. "A large proportion of its weight is supported either by a road tractor or by a detachable front axle assembly known as a dolly." is a necessary extension of this definition explaining that since a semi-trailer has no front axle it needs to be supported at the front. This basic definition distinguishes a semi-trailer from a full trailer which is entirely (or mostly) supported by its own axles. Further explanation is then required, namely:-
3. "A semi-trailer is normally equipped with legs which can be lowered to support it when it is uncoupled." The word "normally" is included here since a few semi-trailers don't have legs and need to be supported by other means e.g. blocks of wood when uncoupled. Apgeraint 18:59, 3 November 2007 (UTC)

I'd suggest that these need to be clarified a little more:
  1. "A semi-trailer is a trailer without a front axle group, and with its rear axle group well behind the centre of the trailer." This distinguishes it from a trailer with a single axle group near centre.
  2. "A large proportion of its weight is supported on top of either a road tractor, the rear of another trailer or a detachable front axle assembly known as a dolly." I'm not entirely happy with the word "large" here, as it implies too much to me. I've added the rear of another trailer to cover B-doubles and the like. I've added that it is carried on top. Otherwise, a trailer which has its single axle group located towards the rear and connects to a hitch ("tagalong") would fit the definition. The wording still isn't ideal because a dolly is, by definition, another trailer, too.
  3. "A semi-trailer is often equipped with legs which can be lowered to support it when it is uncoupled." I would much prefer the word "often" here to "normally".
I'd like to point out that some semi trailers are bolted to the prime mover via a ballrace and rocker feet instead of a quick-release turntable, and such trailers are never fitted with landing legs. There are many such exceptions, and our definition needs to be vague enough to cover them but specific enough to not include other types of trailer. --Athol Mullen 23:45, 3 November 2007 (UTC)

Here are my observations:-
1. A semi trailer is a trailer without a front axle: period. An axle group means two or more axles, so a trailer without a front axle group could still have one front axle so it wouldn't be a semi-trailer, would it?
1b, The rear axle group is not always well behind the centre of the trailer. Look at those in Canada and Michigan for example. Some have a group of up to 6 axles begining immediately behind the trailer legs. At least one axle is in front of the centre of the trailer.
2. The thing that separates the definition of a semi-trailer from that of a full trailer with an axle group near the centre therefore, is the fact that a large proportion of its weight is supported by the tractor or a dolly. You are right however to include that it may also be supported by the rear end of another trailer. I'd like to give a percentage figure on the proportion of weight supported by the tractor but since this varies from country to country and since Wikipedia is inernational this is not possible within the definition. Could be up to 40% though. The proportion is therefore quite large.
3. To say that a semi-trailer is "often" equiped with legs is not really correct since there are very few which are not equiped with legs. Count them and see! The word "often" suggests a smaller proportion, whereas the word "most" means a much greater proportion. Incidentally any trailer which is permanently or semi-permanently attached to tractor is more likely to be known as an "articulated vehicle" and any trailer permanently or semi-permanently attached to another trailer would be known as a "combination trailer". Apgeraint 12:31, 4 November 2007 (UTC)

After having read and replied to your comments it was necessary for me to add the following whilst keeping the definition as clear and unambiguous as possible:- "Some semi-trailers are fitted with a fifth wheel coupling at the tail end so that an additional semi-trailer can be towed. See B-Train." Apgeraint 13:24, 4 November 2007 (UTC)

(edit conflict)

If you haven't looked at my user page, I'd encourage you to do so before you respond.
From the Australian Design Rules definitions (based on UN-ECE regs):
Axle group - either a Single Axle, Tandem Axle Group, Triaxle Group, or Close Coupled Axle Group.
A rear axle group does not in any way imply that there is a front axle or front axle group. For axles to be considered to be a group, there are limits on how far apart they can be. An axle at each end of the trailer would be either considered to be 2 axle groups or a "non-complying axle group" (ie illegal). This is common to both US-FMVSS based regs and UN-ECE regs (and derivatives thereof).
I agree that the first one needs to be clarified a little (I considered it implicit but to a non-technical person, perhaps it isn't):
  1. "A semi-trailer is a trailer without a front axle group, and with the centre of its rear axle group well behind the centre of the trailer."
I've seen various trailer configurations that would put anywhere between about 25% and 60% of the trailer mass onto the towing vehicle. I very nearly suggested something along the lines of typically in the order of 40% of the trailer mass when I was composing my proposed definitions earlier, but removed it because it is too much of an arbitrary figure. My concern with the word large is that it might be interpreted as being "most" or "greater than 50%", but if other editors agree with the use of that word I'm not going to argue the point.
Your comments on "articulated vehicle" and "combination trailer" are obviously a regional variation. In Australia, any truck and trailer combination that incorporates one or more semi trailers is considered to be an "articulated vehicle" whether they are separable or not, and the term "combination trailer" doesn't exist here. A dog trailer (defined as a trailer that is built as a permanently joined combination of semi and dolly) is registered as one trailer. All other combinations are registered as separate vehicles, even if they are bolted together and are inseparable. This also appears to be common to the UN-ECE regulations, which covers most of the world outside the USA.
The frequency with which trailers are or are not equipped with landing legs is also likely to vary significantly on a regional basis but I'm not going to argue that point.
On your last point, I'd point out that some semi trailers have a ringfeder or similar tow coupling hitch at the rear rather than a fifth wheel coupling on top. The tow coupling is then used to tow a dog trailer or a convertor dolly (aka road train dolly) with another semi behind that. --Athol Mullen 14:20, 4 November 2007 (UTC)

I heard the term 'combination trailer' circa 1980. It was a bureaucratic neologism and now it seems that it fell out of use.

The word 'articulated' simply means 'connected by joints' so any vehicle and trailer combination is an articulated vehicle. The Australian definition is correct. Here in France too we use the term véhicule articulé in the same way. You are right to assume that there are regional variations for in the UK only semi-trailer trucks and "bendy" buses are considered to be articulated vehicles and in the USA the term 'articulated vehicle' doesn't even refer to trucks. Wording these articles is very difficult in order to satisfy everyone.

As far as the definition of a semi-trailer is concerned: I wrote it in in simple language so that even a layman can understand and in layman's terms 'axle group' means 'a set of axles close together'. Your extract from the Australian Design Rules definitions confirms this. They simply show that for the purpose of the Design Rules a single axle is considered as an axle group. As you can see the word "group" has not been included after the words "single axle". Apgeraint 20:57, 5 November 2007 (UTC)

[edit] Low-loader

There is no mention of Low-loader which may be a UK-only term. I think the US equivalents are Lowboy and Drop-deck trailer but what is the difference between these two? Biscuittin (talk) 08:12, 6 June 2008 (UTC)