Today, ‘tangent handrail’ is certainly an obscure topic. Until recently, when I taught a seminar on the subject in Seattle, I didn’t think anyone would be interested. I was wrong. At that seminar, hosted by Keith Mathewson of Seattle Fine Woodworking, we had a full house of dedicated craftsmen who came together from all parts of the country for one reason only—to learn something new.
Strangely, in this case, the ‘new thing’ was both old and new, for tangent handrail (once a common vocation) probably hasn’t been practiced, or formally taught, for a couple of generations or more. The challenge was to try to relearn something which was once well known, but is now all but forgotten.
“A variant of the Cylindric method of layout, [the Tangent method] allows for continuous climbing and twisting rails and easings. It was defined from principles set down by architect Peter Nicholson in the 18th century.” (Wikipedia)
So, why would we attempt to use an 18th century system for building handrails? I think it’s fair to say that the majority of stairs being built in America today are still being constructed by small companies, or individual craftsmen who don’t always have six figures to invest in CNC machinery. For those of us who fall into this category (including some fully equipped CNC operators), traditional tangent layout methods are still a viable means for producing continuous and complex hand railing.
The fact remains that the tangent method of laying out and making curved and twisted (wreathed) handrail worked well then, and still works today—you just have to make the effort to learn how. And the effort is worth it. Handrails made with the tangent system are far more beautiful and pleasing than those ‘assembled’ from factory parts.
The Seattle seminar was four days of drafting, and a hands-on workshop. I had come prepared to review and teach nine-to-twelve separate drawings (one for each of the various tangent plan arrangements). What we actually accomplished was two of the drawings and one ‘squared wreath’ for each of us. Some of the guys were able to begin carving the handrail profile (with good results for first-time efforts), but most of our time was spent deciphering the old line system.
We started the first day with an historical overview and introduction to the tangent method, and then proceeded directly to the drafting tables. You can’t do anything without a good drawing. And that will be the focus of this article, too.
Drawing curving handrail is almost more of a challenge than making it, especially since some of the surfaces that must be drawn don’t even exist in reality! But a good drawing is the only way to develop a pattern—called a ‘face mold’—for these custom-made curved and twisting handrail fittings.
What is Tangent Handrail?
Maybe the best way to describe tangent handrail is to describe what it isn’t. There is absolutely no wood bending of any kind, no vertical or horizontal strip-laminating, no steam or chemical forming (or any other means of twisting and torturing wood fibers into submission). The wood (or stone) is simply taken for what it is, and cut and carved to the desired shape. The tangent method simply provides the patterns for accurately accomplishing this work.
What does ‘tangent’ mean?
The first step in understanding the tangent system is understanding what a tangent is! A tangent is simply a straight line that touches the edge of a curve at only one point. It is always perpendicular to a circular arc’s radius. Below is a simple two-dimensional example (“simple” because it only involves a single plane).
When using the tangent handrail system, you must visualize a wreath in three dimensions with tangents that intersect in two planes—one that descends the lower flight of stairs, and one that ascends the upper flight of stairs.
|With the tangents inclined, a diagonal (or ‘oblique’) slice through the cylinder creates an elliptical shape.
And you must be able to draw that wreath in three dimensions if you want to cut it accurately from a single block of wood.
Before getting to the step-by-step instructions for drawing the pattern (or ‘face mold’) for the wreath, watch the following video, so you’ll have a better overview of the theory behind the drawing process.
A Step-by-Step Drawing
The following drawing steps are used to create a two dimensional representation of the three dimensional ‘box’ that is the foundation for tangent handrailing. This example features a 90 degree turning handrail wreath, with equal pitches. Starting with a drawing of the handrail fitting ‘in plan’ (‘in plan’ means when viewed ‘from above,’ like looking at a floor plan), the required information is projected through elevation to the ‘oblique plane.’ The result produces a ‘face mold,’ which is a detailed template for creating this custom handrail piece.
Step 1: The drawing process starts by drawing two intersecting lines that are perpendicular to one another. One horizontal and one vertical, their intersection is labeled point A.
Step 2: Create a square box to represent the plan view of the handrail by drawing lines parallel to both the horizontal and vertical lines. The distance of the offset is the centerline radius of the handrail turn in plan, 5 inches in this example. Note that the parallel vertical line should also project above the horizontal line.
Step 3: Use a compass to draw the centerline of the handrail’s curve in plan. Point C in the drawing (below) is the center of the arc, and the compass is spread to the predetermined radius distance of 5 inches. With the arc drawn, the tangent and spring lines can be identified.
Step 4: Measure out along the horizontal line from point V (the vertex), using the same radius distance used previously (5 inches) to locate point B1. From this point, use a protractor to draw a pitch line at the angle of the stair pitch, 35 degrees in this example. This creates an elevation view of the three dimensional box being drawn.
Step 5: Use a square to draw a line perpendicular to the pitch line that intersects point V.
Step 6: Locate point Bo by swinging an arc from point Vo, with the compass spread to the distance between Vo and B1.
Step 7: Draw a line originating at point Vo that passes through point Bo to define the inclined tangents.
Step 8: Create the parallelogram that makes up the oblique plane (the lid of the box) by drawing lines from points Ao and Bo that are parallel to the inclined tangents.
Step 9: The next step is to determine the bevel angle for the handrail. This is the angle where the handrail’s profile is ‘twisted’ at each end in order to match the profile of the straight raking rails. Using point V as a center, spread the compass until it touches the intersection of the pitch line and the perpendicular line drawn in step 5, and then swing an arc to the base line.
Step 10: Draw the bevel line by connecting the arc intersection on the base line to point B. This line represents the centerline of the handrail profile.
Step 11: Begin creating a box that will encompass the handrail profile by drawing lines parallel to the bevel line. Since the handrail width in this example is 2 1/2 in., the offset is 1 1/4 in. on each side of the bevel line.
Step 12: Finish the box that surrounds the handrail profile by drawing two lines perpendicular to the bevel line to define the height of the profile. In this example, the handrail profile is 1 3/4 in. tall.
Step 13: To determine the minimum required stock size for the wreath block, enclose the squared profile box with a box that is square to the level base line.
Step 14: With the squared handrail profile determined, it’s time to move back to the oblique plane and the creation of the face mold. The inclined tangent lines that extend outside points Bo and Ao represent the centerline of the ‘shanks,’ or straight sections, on either side of the curved portion of the fitting. The widths of the shanks on the face mold are determined by the squared handrail profile and the bevel angle. Use the distance measured along the base line, from the bevel line intersection to the handrail width line intersection, to offset each side of the shank center line. Finish by squaring off the shanks with a perpendicular line; the shank length is arbitrary.
Step 15: Draw ordinate lines for the plan view and oblique plane by drawing lines connecting points C and V, and points Co and Vo.
Step 16: Draw the inner and outer edges of the handrail in plan by drawing arcs centered on point C, offset from the plan centerline by 1/2 of the handrail’s width on each side. The distance is 1 1/4 in. in this example for the 2 1/2 in. wide handrail.
Step 17: Draw a line parallel to the ordinate line in plan. The distance is arbitrary; it will be used as a benchmark for projecting measurements to the oblique plane.
Step 18: Draw a line from the intersection of the previously drawn parallel ordinate line and the tangent line, parallel to the height line, until it intersects the inclined tangent line above.
Step 19: Transfer the intersection point on the inclined tangent line to the opposite inclined tangent line by using a compass to swing an arc centered on point Vo.
Step 20: Draw lines from both points on the inclined tangent lines that are parallel to the ordinate line of the oblique plane.
Step 21: Begin transferring measurements from plan to the oblique plane. Use the distance along the ordinate line in plan from point V to the handrail’s inner edge (Red) to mark point 1 along the oblique ordinate line from point Vo. Use the distance along the parallel benchmark ordinate line in plan, measured from the tangent line to the handrail’s inner edge (Blue) to mark points 2 and 3 up from the inclined tangents, along the lines drawn parallel to the oblique ordinate.
Step 22: Transfer the handrail widths from plan to the oblique plane. Mark point 4 along the oblique ordinate line measuring down from point 1, which is the handrail width along the ordinate line in plan (Red). Mark points 5 and 6 by using the distance measured from the inner to outer handrail edges along the benchmark ordinate line in plan (Blue).
Step 23: Complete the face mold by using a flexible curve to connect points 1, 2, and 3 to the inner edges of the shanks, and points 4, 5, and 6 to the outer edges of the shanks.
The Face Mold
|Now that the drawing is complete we can see and cut out the face mold.
|I often paste the face mold drawing onto a 1/4-in. piece of plywood or hardboard so I can easily transfer information from the pattern to the ‘blank’.
The blank is the actual stock from which the wreath is cut. Watch this video and you’ll see how the blank—before it’s shaped—fits on the oblique plane at the top of the drawing:
Shaping the Wreath
|Working to lines drawn directly on the blank, the waste material is first cut away with the bandsaw. Both the rough convex and concave sides of the rail are now revealed and finished up with a spokeshave and rasp, etc.
Molding the Wreath
The actual carving, or shaping, of the handrail profile is a subject in-and-of-itself, and with varying suggested methods (see Mike Kennedy’s article, “Carving a Volute”). Some of these include hand-held routers, grinders and other ways and means. In the distant past, there was little doubt or discussion as to ‘how to do it.’ Every woodworker had to be reasonably good with his hands, and passable or proficient woodcarving was taken for granted.
In most cases, the excess wood was cleared away by hand, and the profile was simply scraped or ‘scratched’ to shape. A simple shop-made tool for accomplishing this task is called a ‘scratch stock,’ and is still a viable tool. Other handy tools (besides the regular set of carving chisels) include: Quirk routers, hand beaders, and special radius molding planes or shaves.
I use a special molding machine, which I designed and had built some years ago. I rarely have to hand carve anymore, but there are times when only hand-work will do. As long as the profiles are fairly simple, and the wood reasonably soft, hand-carving still works well—especially for occasional supplemental stair parts.
If all of this sounds way too complicated, I might agree with you, except for the fact that I have been doing this, myself, for many years—and I flunked high school algebra and never completed college. I had to figure all this stuff out on my own, down in the basement of the old Los Angeles County Library. Working from very old, brown and brittle ‘reference only books,’ I slowly began to paste it together. Back in the 1970s and ’80s there was absolutely no one to talk to about this stuff, except for a few dead authors like Riddell, Monkton and Ellis. There weren’t any books in print on the subject, and, of course, no Google. Anyway, I suppose if I can do it, so can you.
How long does it take?
A complete set of drawings and templates can take a couple of hours or more—sometimes a full day. But for a single part, I am often done in an hour. After that, it’s out to the workshop to cut wood. The cutting and squaring of a typical wreath piece can take two or three hours, and the machine carving will add, perhaps, another hour. In short, most individual parts are completed within a day, and sometimes before noon. If I have to do any hand carving, it’s usually another full day or so. It is certainly possible to expend a full week on a custom volute.
Why should anyone go to the trouble?
Not everyone should go to the trouble. It is difficult. It is time-consuming. And despite the title of the book, A Simplified Guide to Custom Stairbuilding and Tangent Handrailing, there is absolutely nothing ‘simple’ about it. That said, tangent handrail, or handrail cut from solid stock, does have some very definite advantages when viewed in comparison with today’s typical laminated handrail:
- Handrail cut from solid stock is not subject to bending limitations or restrictions, such as small radii or steep pitches.
- Solid rail does not spring-back, unwind, or de-lam.
- Solid rail has no visible, stripped glue-line issues.
- Natural wood grains and textures are left intact and prominently featured.
- Handrail segments cut from tangent lay-out methods are able to negotiate changes in direction and pitch with predetermined, graceful curves.
- A tangent layout yields the pattern and required dimensions to cut a wreathed rail from the minimum amount of stock without ‘guess work’.
- Difficult handrail butt-joints are pre-cut on the bench and usually square to the plank before the wreath is formed.
There are other advantages, too, but there are also some limitations (you’re not, for example, going to be able to cut a 24-in. piece of curved rail from a single board). Perhaps the greatest single advantage is the ability to produce a product which your local competitor can’t. This can translate into more work, and more money for your work! It can also place your company within a class of clientele who demand custom work and are willing and able to pay a premium for it.
• • •
Appreciation (rather than a bio)
I hesitate to mention any names, but I’d like to acknowledge a few of the guys who attended the class; without their help, the class, and this article, might not have been possible:
Billy, who booked us a room in a hostel (what’s a hostel?). I don’t know, but there were four of us on two bunk beds in a room no bigger than a condo kitchen. This was great fun!
Josh, who drove us all around in his monster pickup truck, complete with camper shell and lumber rack, and learned the hard way that it really doesn’t fit in the airport parking structure!
Mike, who always asked the best questions, and fixed his own wreath after I nearly wrecked it on the band saw.
Troy, Kyle and Doug, who figured out most of this on their own before coming to class (I know they’ll do well).
Steve, who sat quietly at his computer most of the time, and then went back and did something neat on his CNC.
Al, who drove me to the airport (he’s smarter than most of us, I think).
Brad, who really is smarter than all of us.
Drew, who finally drew it correctly.
Lavrans, who bought more than a round or two.
Dave, who kept me company.
Katz, who documented the whole mess, and continues to publish Pulitzer Prize-winning pieces like this one.
Todd Murdock, for the killer SketchUp drawings (he wasn’t at the class, but he did a lot of great work on this article!).
And Keith, who just furnished me the menu (“These were all produced by tenants in my catering kitchen”):
Wed. – Chinese Dim Sum
Thurs. – Salvadoran Chicken, corn salsa, rice and salad
Fri. – Ethiopian chicken, beef, goat, salad, mango & avocado drink
Sat. – tamales with rice & beans
Sun. – Northern Mexican tacos, sopitos, quesadilla, carrot cake, and Mexican tea cookies.
Who can top that?