How would you notate an extra long note for strings in a way which allows it to be bowed multiple times?

Question

When composing for strings, sometimes I'd like to write a note which is a combination of very loud and very long—something that can't be played on one bow alone. If I write a long note with ties, sometimes the performer interprets that as needing to have one bow, which results in a quieter sound. If I split the note into smaller ones, I feel like a violinist sight reading would give both notes an attack.

Is there a certain way you would notate a long note that can have multiple bows, but still phrased as one continuous note?

Answer 1

Here are the last few bars of Elgar's Salut d'Amour.

The last 8 bars are one long continuous E played on the violin with multiple bows.

Here is a 10 year-old violinist showing you how it is done:

Answer 2

1. If it's notated long enough and you make your desire for a loud dynamic clear enough, a smart player will go ahead and change bow as necessary
2. That's more true in an orchestral context, where people changing bow at random times will be less noticeable. A solo or chamber music part might be more inclined to try to challenge themself to save bow and still project.
3. If you want to be explicit, best to indicate it in some way. Printing multiple down-bow and up-bow symbols over the same note communicates this, or add a textual direction like "change bow freely" or, I guess, if it has to be Italian, maybe arco ad libitum.