why use text leaders in cad plans

[lambertb]

So we are doing some plans production standards. One thought was why are leaders needed if all the object are called out witha  station and offset in civil engineering plans? Anyone care to chime in  on the subjecct question?

Why use text leaders in cad plans?

Thanks

[mathewkol]

How about a manhole? How else would you know which manhole was #8 if you didn't have a leader pointing at it?

[mathewkol]

I suppose one could just have a table that lists all the manholes and their sta and elev, but I think that is less intuative and harder to read.

[Neilw_05]

The main purpose of leaders is to deal with overlapping annotations and to move text away from encroaching on features. Think about it.

[Joe-Bouza]

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@mathewkol wrote:
I suppose one could just have a table that lists all the manholes and their sta and elev, but I think that is less intuative and harder to read.

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Bingo!

Granted if everything is legalized and tabulated clearly there may not be a real need for call outs, but that is not how we humans work <G> we need it spelled out for us.

If we were so smart we wouldn't require 13 years of primary, middle and high school plus 4 to 8 years of college, would we?

Statistically we are very dense. That's why we need leader text, IMHO.

[lambertb]

Thanks everyone. It seems liek you all use leaders.

Leaders seem to be used to pull text away from the middle of the street so to speak. If we took the leaders away from the inlets, the station and offset doesn't direct the eye to its location. And the manhole info in the middle of the street just seems out of place and can get lost. I am dealing with both camps and am trying to find a happy place.

[Joe-Bouza]

Perhap the structure number only in plan and the station offset in the table.

It doesn't fool my I - I follow the leader ( I guess that game meant something after all)

IMHO forcing left justified text with a leader on the right is more confusing to look at. I know its an ancient drafting tradition passed down along the ages.... Maybe it works on architectural drawing but I don't bother.

[Neilw_05]

So what is the argument AGAINST leaders?

[lambertb]

Against - extra lines with no meaning. The station and offset already identify the obect.

[Neilw_05]

I am totally in your camp Joe. Text should be justified so as to form an even frame around the graphics for visual appeal. Consider a mechanical part as a clear example. The annotation around the right side of the part should be left justified and around the left side of the part it should be right justified. The result is an even gap or frame around the part. Compare that with having left justified text around the left side of the part which will be jagged and uneven.

[Neilw_05]

The leaders serve an important purpose here, no question about that. The software takes care of the leaders so no extra work.

[troma]

We put a small amount of text right next to the object with no leader, "CB" for a catchbasin or "FH" for a fire hydrant. Then, in a box a little way back, we put information like Station, Offset, Elevation etc. as necessary. No leaders for them.
But we do use leaders for many things. Rule of thumb: one leader should not cross another. All should be similar angles and distances from the object if possible. And please, please align the text to the same side as the leader comes out! That "INL 7A" & "INL 7B" on your drawing look obscene! Same goes for the manhole labels without leaders: the text should be right-justified because it is referring to an object on its right.

[dsigman]

I'm not sure I can explain this well enough since the story happened over 10 years ago. But I worked on a job staking a high school and all the manholes etc were listed with coordinates in a table. Because the plans weren't very well done I had to do a lot of field calculations. I had to constantly flip back and forth between the plan sheet and the table which was on another sheet. It doubled or tripled the time to do field calculations. If the job had been laid out in the normal way everything would have been on one sheet. Each manhole, DI, etc would have been labeled at the point where it fell and not on a separate sheet.

[AllenJessup]

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@dsigman wrote:

I had to constantly flip back and forth between the plan sheet and the table which was on another sheet. It doubled or tripled the time to do field calculations. 

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Exactly. I've been there myself. Even just checking consultants plans in the office is painful if the table is 20 pages away from the plan sheet you're checking.
 

You can minimize the amount of leaders. I certainly don't use them if I can label something without them. But sometimes you just need to get the text out in the clear so as not to mask too much. Also it can bee a neater look. The information may be the same but if you've got a cluttered looking plan. It doesn't look professional. I know. No leaders at all and just tables would be "less cluttered" but my reasons above still hold.

One way we try to simplify things is to have a table on each sheet that references only those structures or points shown on the sheet. Not a massive table at the beginning or end of each sub-discipline.

Allen

[jggerth1]

i will disagree about ever using right justification.  Unless using a right-to-left or bidrirectinal language, all text, notes callouts should always be left justified IMO.  We spend decades learning to read and 99+% is left justified.

Ragged-right is the norm, ragged left is the rare exception. and the historical inability of CAD to properly handle leaders to the right is insufficient reason to settle for ragged left.  Many of my drawings end up as dense as a phone book, and trying to read that with ragged-left justification would be a nightmare,

[Neilw_05]

One big downside to left justified on right leaders is when you have to change annotation scale. All the text expands in the wrong direction and encroaches on the graphics.